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2 [bey-siz]
plural of base1.


1 [beys]
the bottom support of anything; that on which a thing stands or rests: a metal base for the table.
a fundamental principle or groundwork; foundation; basis: the base of needed reforms.
the bottom layer or coating, as of makeup or paint.
the distinctively treated portion of a column or pier below the shaft or shafts. See diag. under column.
the distinctively treated lowermost portion of any construction, as a monument, exterior wall, etc.
Botany, Zoology.
the part of an organ nearest its point of attachment.
the point of attachment.
the principal element or ingredient of anything, considered as its fundamental part: face cream with a lanolin base; paint with a lead base.
that from which a commencement, as of action or reckoning, is made; a starting point or point of departure.
any of the four corners of the diamond, especially first, second, or third base. Compare home plate.
a square canvas sack containing sawdust or some other light material, for marking first, second, or third base.
a starting line or point for runners, racing cars, etc.
(in hockey and other games) the goal.
a fortified or more or less protected area or place from which the operations of an army or an air force proceed.
a supply installation for a large military force.
Geometry. the line or surface forming the part of a figure that is most nearly horizontal or on which it is supposed to stand.
the number that serves as a starting point for a logarithmic or other numerical system.
a collection of subsets of a topological space having the property that every open set in the given topology can be written as the union of sets of the collection.
a collection of neighborhoods of a point such that every neighborhood of the point contains one from the collection.
a collection of sets of a given filter such that every set in the filter is contained in some set in the collection.
Also called base line. Surveying, See under triangulation ( def 1 ).
vehicle ( def 10 ).
Also called carrier. inert matter, used in the preparation of lakes, onto which a coloring compound is precipitated.
Photography. a thin, flexible layer of cellulose triacetate or similar material that holds the light-sensitive film emulsion and other coatings, especially on motion-picture film.
a compound that reacts with an acid to form a salt, as ammonia, calcium hydroxide, or certain nitrogen-containing organic compounds.
the hydroxide of a metal or of an electropositive element or group.
a group or molecule that takes up or accepts protons.
a molecule or ion containing an atom with a free pair of electrons that can be donated to an acid; an electron-pair donor.
any of the purine and pyrimidine compounds found in nucleic acids: the purines adenine and guanine and the pyrimidines cytosine, thymine, and uracil.
Grammar. the part of a complex word, consisting of one or more morphemes, to which derivational or inflectional affixes may be added, as want in unwanted or biolog- in biological. Compare root1 ( def 12 ), stem1 ( def 16 ).
Linguistics. the component of a generative grammar containing the lexicon and phrase-structure rules that generate the deep structure of sentences.
an electrode or terminal on a transistor other than the emitter or collector electrodes or terminals.
the part of an incandescent lamp or electron tube that includes the terminals for making electrical connection to a circuit or power supply.
Stock Exchange. the level at which a security ceases a decline in price.
Heraldry. the lower part of an escutcheon.
bases, Armor. a tonlet formed of two shaped steel plates assembled side by side.
Jewelry. pavilion ( def 6 ).
in base, Heraldry. in the lower part of an escutcheon.
serving as or forming a base: The walls will need a base coat and two finishing coats.
verb (used with object), based, basing.
to make or form a base or foundation for.
to establish, as a fact or conclusion (usually followed by on or upon ): He based his assumption of her guilt on the fact that she had no alibi.
to place or establish on a base or basis; ground; found (usually followed by on or upon ): Our plan is based on a rising economy.
to station, place, or situate (usually followed by at or on ): He is based at Fort Benning. The squadron is based on a carrier.
verb (used without object), based, basing.
to have a basis; be based (usually followed by on or upon ): Fluctuating prices usually base on a fickle public's demand.
to have or maintain a base: I believe they had based on Greenland at one time.
get to first base. first base ( def 2 ).
off base,
Baseball. not touching a base: The pitcher caught him off base and, after a quick throw, he was put out by the second baseman.
Informal. badly mistaken: The police were way off base when they tried to accuse her of the theft.
on base, Baseball. having reached a base or bases: Two men are on base.
touch base with, to make contact with: They've touched base with every political group on campus.

1275–1325; Middle English (noun) < Middle French < Latin basis basis; cf. prisoner's base

unbased, adjective
well-based, adjective

1. Base, basis, foundation refer to anything upon which a structure is built and upon which it rests. Base usually refers to a literal supporting structure: the base of a statue. Basis more often refers to a figurative support: the basis of a report. Foundation implies a solid, secure understructure: the foundation of a skyscraper or a rumor.


noun, plural bases [bey-seez] .
the bottom or base of anything; the part on which something stands or rests.
anything upon which something is based; fundamental principle; groundwork.
the principal constituent; fundamental ingredient.
a basic fact, amount, standard, etc., used in making computations, reaching conclusions, or the like: The nurse is paid on an hourly basis. He was chosen on the basis of his college grades.
Mathematics. a set of linearly independent elements of a given vector space having the property that every element of the space can be written as a linear combination of the elements of the set.

1525–35; < Latin < Greek básis step, place one stands on, pedestal, equivalent to ba-, base of baínein to walk, step (akin to come) + -sis -sis; cf. base1

1, 2. See base1.


2 [beys]
adjective, baser, basest.
morally low; without estimable personal qualities; dishonorable; meanspirited; selfish; cowardly.
of little or no value; worthless: hastily composed of base materials.
debased or counterfeit: an attempt to eliminate the base coinage.
characteristic of or befitting an inferior person or thing.
of illegitimate birth.
not classical or refined: base language.
Old English Law. held by tenure less than freehold in return for a service viewed as somewhat demeaning to the tenant.
of humble origin or station.
of small height.
low in place, position, or degree: base servitude.
Obsolete. deep or grave in sound; bass: the base tones of a piano.
Music Obsolete, bass1 ( defs 3, 4 ).

1350–1400; Middle English bas < Old French < Late Latin bassus low, short, perhaps of Oscan orig.

basely, adverb
baseness, noun

1. despicable, contemptible. See mean2. 2. poor, inferior, cheap, tawdry. 3. fake, spurious. 4. servile, ignoble, abject, slavish, menial.


noun Surveying, Navigation.
a technique for establishing the distance between any two points, or the relative position of two or more points, by using such points as vertices of a triangle or series of triangles, such that each triangle has a side of known or measurable length (base or base line) that permits the size of the angles of the triangle and the length of its other two sides to be established by observations taken either upon or from the two ends of the base line.
the triangles thus formed and measured.

1810–20; < Medieval Latin triangulātiōn- (stem of triangulātiō) the making of triangles. See triangulate, -ion

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To Bases
World English Dictionary
base1 (beɪs)
1.  the bottom or supporting part of anything
2.  the fundamental or underlying principle or part, as of an idea, system, or organization; basis
3.  a.  a centre of operations, organization, or supply: the climbers made a base at 8000 feet
 b.  (as modifier): base camp
4.  a centre from which military activities are coordinated
5.  anything from which a process, as of measurement, action, or thought, is or may be begun; starting point: the new discovery became the base for further research
6.  the main ingredient of a mixture: to use rice as a base in cookery
7.  See also Lewis base a chemical compound that combines with an acid to form a salt and water. A solution of a base in water turns litmus paper blue, produces hydroxyl ions, and has a pH greater than 7. Bases are metal oxides or hydroxides or amines
8.  biochem any of the nitrogen-containing constituents of nucleic acids: adenine, thymine (in DNA), uracil (in RNA), guanine, or cytosine
9.  a medium such as oil or water in which the pigment is dispersed in paints, inks, etc; vehicle
10.  the inorganic material on which the dye is absorbed in lake pigments; carrier
11.  biology
 a.  the part of an organ nearest to its point of attachment
 b.  the point of attachment of an organ or part
12.  the bottommost layer or part of anything
13.  architect
 a.  the lowest division of a building or structure
 b.  the lower part of a column or pier
14.  another word for baseline
15.  the lower side or face of a geometric construction
16.  maths
 a.  See place-value the number of distinct single-digit numbers in a counting system, and so the number represented as 10 in a place-value system: the binary system has two digits, 0 and 1, and 10 to base two represents 2
 b.  (of a logarithm or exponential) the number whose powers are expressed: since 1000 = 10³, the logarithm of 1000 to base 10 is 3
 c.  (of a mathematical structure) a substructure from which the given system can be generated
 d.  the initial instance from which a generalization is proven by mathematical induction
17.  logic, maths Also called: base clause the initial element of a recursive definition, that defines the first element of the infinite sequence generated thereby
18.  linguistics
 a.  a root or stem
 b.  See base component
19.  electronics the region in a transistor between the emitter and collector
20.  photog the glass, paper, or cellulose-ester film that supports the sensitized emulsion with which it is coated
21.  heraldry the lower part of the shield
22.  jewellery the quality factor used in pricing natural pearls
23.  a starting or finishing point in any of various games
24.  baseball any of the four corners of the diamond, which runners have to reach in order to score
25.  the main source of a certain commodity or element: a customer base; their fan base
26.  informal (US), (Canadian) get to first base to accomplish the first stage in a project or a series of objectives
27.  informal (US), (Canadian) off base wrong or badly mistaken
28.  touch base to make contact
vb (often foll by at or in)
29.  (tr foll by on or upon) to use as a basis (for); found (on): your criticisms are based on ignorance
30.  to station, post, or place (a person or oneself)
[C14: from Old French, from Latin basis pedestal; see basis]

base2 (beɪs)
1.  devoid of honour or morality; ignoble; contemptible
2.  of inferior quality or value
3.  debased; alloyed; counterfeit: base currency
4.  English history
 a.  (of land tenure) held by villein or other ignoble service
 b.  holding land by villein or other ignoble service
5.  archaic born of humble parents; plebeian
6.  archaic illegitimate
adj, —n
7.  music an obsolete spelling of bass
[C14: from Old French bas, from Late Latin bassus of low height, perhaps from Greek bassōn deeper]

bases1 (ˈbeɪsiːz)
the plural of basis

bases2 (ˈbeɪsɪz)
the plural of base

basis (ˈbeɪsɪs)
n , pl -ses
1.  something that underlies, supports, or is essential to something else, esp an abstract idea
2.  a principle on which something depends or from which something has issued
3.  maths (of a vector space) a maximal set of linearly independent vectors, in terms of which all the elements of the space are uniquely expressible, and the number of which is the dimension of the space: the vectors x, y and z form a basis of the 3-dimensional space all members of which can be written as ax + by + cz
[C14: via Latin from Greek: step, from bainein to step, go]

triangulation (traɪˌæŋɡjʊˈleɪʃən)
1.  a method of surveying in which an area is divided into triangles, one side (the base line) and all angles of which are measured and the lengths of the other lines calculated trigonometrically
2.  the network of triangles so formed
3.  the fixing of an unknown point, as in navigation, by making it one vertex of a triangle, the other two being known
4.  chess a key manoeuvre in the endgame in which the king moves thrice in a triangular path to leave the opposing king with the move and at a disadvantage

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
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Word Origin & History

"bottom, foundation, pedestal," early 14c., from O.Fr. bas "depth" (12c.), from L. basis "foundation," from Gk. basis "step, pedestal," from bainein "to step" (see come). The military sense is from 1860. The chemical sense (1810) was introduced in French 1754 by Fr. chemist
Guillaume-François Rouelle (1703-1770). The verb meaning "to place on a foundation" is from 1841.

late 14c., from O.Fr. bas (Mod.Fr. bas) "low, lowly, mean," from L.L. bassus "thick, stumpy, low" (used only as a cognomen in classical Latin, humilis being there the usual word for "low in stature or position"), possibly from Oscan, or Celtic, or related to Gk. basson, comparative of bathys "deep."
Figurative sense of "low in the moral scale" is first attested 1530s in English, earlier "servile" (1520s). Base metals (c.1600) were worthless in contrast to noble or precious metals.

1570s, from L. basis "foundation," from Gk. basis "a step, stand, base, that whereon one stands," from bainein "go, step" (see come).
Online Etymology Dictionary, © 2010 Douglas Harper
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American Heritage
Medical Dictionary

base (bās)

  1. The part of an organ nearest its point of attachment.

  2. A fundamental ingredient; a chief constituent of a mixture.

  3. Any of a large class of compounds, including the hydroxides and oxides of metals, having a bitter taste, a slippery solution, the capacity to turn litmus blue, and to react with acids to form salts.

  4. A molecular or ionic substance capable of combining with a proton to form a new substance. Also called Brønsted base.

  5. A nitrogen-containing organic compound that combines in such a manner.

  6. A substance that provides a pair of electrons for a covalent bond with an acid.

basis ba·sis (bā'sĭs)
n. pl. ba·ses (-sēz')
The foundation upon which something, such as an anatomical part, rests.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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American Heritage
Science Dictionary
base   (bās)  Pronunciation Key 
  1. Chemistry

    1. Any of a class of compounds that form hydroxyl ions (OH) when dissolved in water, and whose aqueous solutions react with acids to form salts. Bases turn red litmus paper blue and have a pH greater than 7. Their aqueous solutions have a bitter taste. Compare acid.

    2. See nitrogen base.

    3. The side or face of a geometric figure to which an altitude is or is thought to be drawn. The base can be, but is not always, the bottom part of the figure.

    4. The number that is raised to various powers to generate the principal counting units of a number system. The base of the decimal system, for example, is 10.

    5. The number that is raised to a particular power in a given mathematical expression. In the expression an, a is the base.

  2. Mathematics

    1. The side or face of a geometric figure to which an altitude is or is thought to be drawn. The base can be, but is not always, the bottom part of the figure.

    2. The number that is raised to various powers to generate the principal counting units of a number system. The base of the decimal system, for example, is 10.

    3. The number that is raised to a particular power in a given mathematical expression. In the expression an, a is the base.

basis   (bā'sĭs)  Pronunciation Key 
Plural bases (bā'sēz')
A set of independent vectors whose linear combinations define a vector space, such as a reference frame used to establish a coordinate system.
triangulation   (trī-āng'gyə-lā'shən)  Pronunciation Key 
A method of determining the relative positions of points in space by measuring the distances, and sometimes angles, between those points and other reference points whose positions are known. Triangulation often involves the use of trigonometry. It is commonly used in the navigation of aircraft and boats, and is the method used in the Global Positioning System , in which the reference points are satellites.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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American Heritage
Cultural Dictionary

base definition

Any of a number of bitter-tasting, caustic materials. Technically, a material that produces negative ions in solution. A base is the opposite of an acid and has a pH of 7 to 14. A given amount of a base added to the same amount of an acid neutralizes the acid; water and a salt are produced. Alkalis are bases; ammonia is a common base.

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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Example sentences
Let's talk about the number of foreign military bases and what they cost.
The mostly white bases to the outer tail feathers form distinctive white tail
  patches visible from underneath or when in flight.
It is prevalent around college campuses and military bases.
All the landers were left behind, the bases remaining where they touched down.
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