a

A, a

[ey]
noun, plural A's or As, a's or as.
1.
the first letter of the English alphabet, a vowel.
2.
any spoken sound represented by the letter A or a, as in bake, hat, father, or small.
3.
something having the shape of an A .
4.
a written or printed representation of the letter A or a.
5.
a device, as a printer's type, for reproducing the letter A or a.
Idioms
6.
from A to Z, from beginning to end; thoroughly; completely: He knows the Bible from A to Z.
7.
not know from A to B, to know nothing; be ignorant.
Dictionary.com Unabridged

a

1 [uh; when stressed ey]
indefinite article
1.
not any particular or certain one of a class or group: a man; a chemical; a house.
2.
a certain; a particular: one at a time; two of a kind; A Miss Johnson called.
3.
another; one typically resembling: a Cicero in eloquence; a Jonah.
4.
one (used before plural nouns that are preceded by a quantifier singular in form): a hundred men (compare hundreds of men ); a dozen times (compare dozens of times ).
5.
indefinitely or nonspecifically (used with adjectives expressing number): a great many years; a few stars.
6.
one (used before a noun expressing quantity): a yard of ribbon; a score of times.
7.
any; a single: not a one.

Origin:
Middle English; orig. preconsonantal phonetic variant of an1


In both spoken and written English the choice of a1 or an1 is determined by the initial sound of the word that follows. Before a consonant sound, a is used; before a vowel sound, an: a book, a rose; an apple, an opera. Problems arise occasionally when the following word begins with a vowel letter but actually starts with a consonant sound, or vice versa. Some words beginning with the vowel letter u and all words beginning with the vowel letters eu are pronounced with a beginning consonant sound, as if the first letter were y: a union; a European. Some other spellings that begin with a vowel letter may also stand for an initial consonant sound: a ewe; a ewer. The words one and once and all compounds of which they are the first element begin with a w sound: a one-room apartment; a once-famous actor.
The names of the consonant letters f, h, l, m, n, r, s, and x are pronounced with a beginning vowel sound. When these letters are used as words or to form words, they are preceded by an: to rent an L-shaped studio; to fly an SST. The names of the vowel letter u and the semivowel letters w and y are pronounced with a beginning consonant sound. When used as words, they are preceded by a: a U-turn; The plumber installed a Y in the line.
In some words beginning with the letter h, the h is not pronounced; the words actually begin with a vowel sound: an hour; an honor. When the h is strongly pronounced, as in a stressed syllable at the beginning of a word, it is preceded by a: a history of the Sioux; a hero sandwich. (In former times an was used before strongly pronounced h in a stressed first syllable: an hundred.) Such adjectives as historic, historical, heroic, and habitual, which begin with an unstressed syllable and often with a silent or weakly pronounced h, are commonly preceded by an, especially in British English. But the use of a rather than an is widespread in both speech and writing: a historical novel; a habitual criminal. Hotel and unique are occasionally preceded by an, but this use is increasingly old-fashioned. Although in some dialects an has yielded to a in all cases, edited writing reflects usage as described above.

a

2 [uh; when stressed ey]
preposition
each; every; per: ten cents a sheet; three times a day.

Origin:
orig. Middle English a, preconsonantal variant of on (see a-1); confused with a1

a

3 [uh]
preposition
Pronunciation spelling. a reduced, unstressed form of of (often written as part of a single, unhyphenated word): cloth a gold; time a day; kinda; sorta.

Origin:
Middle English; unstressed preconsonantal variant of of1

a

4 [uh]
auxiliary verb Pronunciation Spelling.
a reduced, unstressed form of auxiliary have, following some modals, as might, should, could, would, and must (usually written as part of a single, unhyphenated word): We shoulda gone.
Compare of2.


Origin:
Middle English; phonetic variant of have

a

5 [uh, a, ah]
pronoun British Dialect.
1.
2.
3.
4.
5.
I.

Origin:
Middle English a, ha

a'

[ah, aw]
adjective
Scot. all: for a' that.
Also, a.

A

1.
Electricity. ampere; amperes.
2.
Physics. angstrom.
4.
British. arterial (used with a road number to designate a major highway): Take the A525 to Ruthin.

A

Symbol.
1.
the first in order or in a series.
2.
(sometimes lowercase) (in some grading systems) a grade or mark, as in school or college, indicating the quality of a student's work as excellent or superior.
3.
(sometimes lowercase) (in some school systems) a symbol designating the first semester of a school year.
4.
Music.
a.
the sixth tone in the scale of C major or the first tone in the relative minor scale, A minor.
b.
a string, key, or pipe tuned to this tone.
c.
a written or printed note representing this tone.
d.
(in the fixed system of solmization) the sixth tone of the scale of C major, called la.
e.
the tonality having A as the tonic note.
5.
Physiology. a major blood group, usually enabling a person whose blood is of this type to donate blood to persons of group A or AB and to receive blood from persons of O or A. Compare ABO system.
6.
(sometimes lowercase) the medieval Roman numeral for 50 or 500. Compare Roman numerals.
7.
Chemistry. (formerly) argon.
8.
Chemistry, Physics. mass number.
9.
Biochemistry.
a.
adenine.
b.
alanine.
11.
British. a designation for a motion picture recommended as suitable for adults. Compare AA ( def 5 ), U ( def 5 ), X ( def 9 ).
12.
a proportional shoe width size, narrower than B and wider than AA.
13.
a proportional brassiere cup size, smaller than B and larger than AA.
14.
a quality rating for a corporate or municipal bond, lower than AA and higher than BBB.

a

Measurements.
are; ares.

a

Symbol, Logic.

Å

Symbol, Physics.

A-

atomic (used in combination): A-bomb; A-plant.

a-

1
a reduced form of the Old English preposition on, meaning “on,” “in,” “into,” “to,” “toward,” preserved before a noun in a prepositional phrase, forming a predicate adjective or an adverbial element (afoot; abed; ashore; aside; away ), or before an adjective (afar; aloud; alow ), as a moribund prefix with a verb (acknowledge ), and in archaic and dialectal use before a present participle in -ing (set the bells aringing ); and added to a verb stem with the force of a present participle (ablaze; agape; aglow; astride; and originally, awry ).

Origin:
Middle English, late Old English; cf. a2, nowadays

a-

2
a reduced form of the Old English preposition of: akin; afresh; anew.

Origin:
Middle English; see a3

a-

3
an old point-action prefix, not referring to an act as a whole, but only to the beginning or end: She arose (rose up). They abided by their beliefs (remained faithful to the end).

Origin:
Middle English; Old English a- (unstressed), ǣ-, ā-, ō- (stressed; see abb, woof1, oakum), rarely or- (see ordeal) ≪ Germanic *uz- < unstressed Indo-European *uss- < *ud-s, akin to out; in some cases confused with a-4, as in abridge

a-

4
variant of ab- before p and v: aperient; avert.

Origin:
Middle English < Latin ā-, a- (variant of ab- ab-); in some words < French a- < Latin ab-, as in abridge

a-

5
variant of ad-, used: (1) before sc, sp, st (ascend ) and (2) in words of French derivation (often with the sense of increase, addition): amass.

Origin:
Middle English, in some words < Middle French a- < Latin ad- prefix or ad preposition (see ad-), as in abut; in others < Latin a- (variant of ad- ad-), as in ascend

a-

6
variant of an-1. before a consonant, meaning “not,” “without”: amoral; atonal; achromatic.

-a

1
a plural ending of nouns borrowed from Greek and Latin: phenomena; criteria; data; errata; genera.

-a

2
a feminine singular ending of nouns borrowed from Latin and Greek, also used in Neo-Latin coinages to Latinize bases of any origin, and as a Latin substitute for the feminine ending - ē of Greek words: anabaena; cinchona; pachysandra.

-a

3
an ending of personal names forming feminines from masculines: Georgia; Roberta.

Origin:
< L feminine -a (see -a2), as Claudia, feminine of Claudius

-a

4
a suffix designating the oxide of the chemical element denoted by the stem: alumina; ceria; thoria.

Origin:
probably generalized from the -a of magnesia

A.

1

Origin:
< Latin annō, ablative of annus

A.

2

Origin:
< Latin ante

A.

3
3.
acre; acres.

a.

1

Origin:
< Latin annō, ablative of annus

a.

2

Origin:
< Latin ante

a.

3
2.
acre; acres.
5.
6.
ampere; amperes.
9.
are; ares.
10.
Baseball. assist; assists.

Bronzino

[brawn-dzee-naw]
noun
Agnolo (di Cosimo di Mariano) [ah-nyaw-law dee kaw-zee-maw dee mah-ryah-naw] , 1502–72, Italian painter.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To A
Collins
World English Dictionary
a or A (eɪ)
 
n , pl a's, A's, As
1.  the first letter and first vowel of the modern English alphabet
2.  any of several speech sounds represented by this letter, in English as in take, bag, calm, shortage, or cobra
3.  Also called: alpha the first in a series, esp the highest grade or mark, as in an examination
4.  from A to Z from start to finish, thoroughly and in detail
 
A or A
 
n

a1 (ə, (stressed or emphatic) eɪ)
 
determiner (indefinite article; used before an initial consonant) (preceded by once, twice, several times, etc)
1.  used preceding a singular countable noun, if the noun is not previously specified or known: a dog; a terrible disappointment
2.  used preceding a proper noun to indicate that a person or thing has some of the qualities of the one named: a Romeo; a Shylock
3.  used preceding a noun or determiner of quantity: a cupful; a dozen eggs; a great many; to read a lot
4.  used preceding a noun indicating a concrete or abstract thing capable of being divided: half a loaf; a quarter of a minute
5.  each or every; per: once a day; fifty pence a pound
6.  a certain; one: to change policy at a stroke; a Mr Jones called
7.  (preceded by not) any at all: not a hope

a2 (ə)
 
vb
an informal or dialect word for have : they'd a said if they'd known

a3 (ə)
 
prep
(usually linked to the preceding noun) an informal form of of : sorta sad; a kinda waste

a4
 
symbol for
1.  acceleration
2.  are(s) (metric measure of land)
3.  atto-
4.  chess See algebraic notation

A
 
symbol for
1.  music
 a.  a note having a frequency of 440 hertz (A above middle C) or this value multiplied or divided by any power of 2; the sixth note of the scale of C major
 b.  a key, string, or pipe producing this note
 c.  the major or minor key having this note as its tonic
2.  a human blood type of the ABO group, containing the A antigen
3.  (in Britain) a major arterial road: the A3 runs from London to Portsmouth
4.  formerly, in Britain
 a.  a film certified for viewing by anyone, but which contains material that some parents may not wish their children to see
 b.  (as modifier): an A film
5.  mass number
6.  the number 10 in hexadecimal notation
7.  cards ace
8.  chem argon (now superseded by Ar)
9.  ampere(s)
10.  Also: at ampere-turn
11.  absolute (temperature)
12.  (in circuit diagrams) ammeter
13.  area
14.  (in combination) atomic: an A-bomb; an A-plant
15.  chem affinity
16.  biochem adenine
17.  logic E I Compare O a universal affirmative categorical proposition, such as all men are mortal: often symbolized as SaP
18.  a.  a person whose job is in top management, or who holds a senior administrative or professional position
 b.  See also occupation groupings (as modifier): an A worker
 
abbreviation for
19.  Austria (international car registration)
 
[from Latin a(ffirmo) I affirm]

Å
 
symbol for
angstrom unit

A.
 
abbreviation for
1.  acre(s) or acreage
2.  America(n)
3.  answer

a', aa or aw (ɔː)
 
determiner
(Scot) variants of all
 
aa, aa or aw
 
determiner
 
aw, aa or aw
 
determiner

a- or (before a vowel) an-1
 
prefix
not; without; opposite to: atonal; asocial
 
[from Greek a-, an- not, without]
 
an- or (before a vowel) an-1
 
prefix
 
[from Greek a-, an- not, without]

a-2
 
prefix
1.  on; in; towards: afoot; abed; aground; aback
2.  literary, archaic or (used before a present participle) in the act or process of: come a-running; go a-hunting
3.  in the condition or state of: afloat; alive; asleep

Bronzino (bronˈdziːno)
 
n
Il, real name Agnolo di Cosimo. 1503--72, Florentine mannerist painter

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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Etymonline
Word Origin & History

a
indefinite article, c.1150, a variation of O.E. an (see an) in which the -n- began to disappear before consonants, a process mostly complete by mid-14c. The -n- also was retained before words beginning with a sounded -h- until c.1600; it still is retained by many writers before
unaccented syllables in h- or (e)u-, but is now no longer normally spoken as such. The -n- also lingered (especially in southern England dialect) before -w- and -y- through 15c.

a
as in twice a day, etc., from O.E. an "on," in this case "on each." The sense was extended from time to measure, price, place, etc. The habit of tacking a onto a gerund (as in a-hunting we will go) died out 18c.

a-
in native (derived from O.E.) words, it most commonly represents O.E. an "on" (see a (2)), as in alive, asleep, abroad, ashore, etc., forming adjectives and adverbs from nouns; but it also can be M.E. of, as in anew, abreast (1590s); or a reduced form of O.E. pp. prefix ge-, as
in aware; or the O.E. intens. a-, as in arise, awake, ashame, marking a verb as momentary, a single event. In words from Romanic languages, often it represents L. ad- "to, at."
"[I]t naturally happened that all these a- prefixes were at length confusedly lumped together in idea, and the resultant a- looked upon as vaguely intensive, rhetorical, euphonic, or even archaic, and wholly otiose." [OED]

a-
prefix meaning "not," from L. a-, short for ab "away from" (cf. avert), or its cognate, Gk. a-, short for apo "away from, from," both cognate with Skt. apa "away from," Goth. af, O.E. of.

a-
prefix meaning "not," from Gk. a-, an- "not," from PIE base *ne "not" (see un-).
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

a abbr.

  1. area

  2. asymmetrical

  3. specific absorption coefficient (often italic)

  4. systemic arterial blood (used as a subscript)

  5. total acidity

A abbr.

  1. absorbance (often italic)

  2. alveolar gas (used as a subscript)

  3. adenine

  4. ammeter

  5. AMP (in polynucleotides)

  6. ampere

  7. angstrom

  8. area

a- or an-
pref.
Without; not: acellular.

Å abbr.
angstrom

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
A  
Abbreviation of adenine, ampere, angstrom, area
Å  
Abbreviation of angstrom
a-  
A prefix meaning "without" or "not" when forming an adjective (such as amorphous, without form, or atypical, not typical), and "absence of" when forming a noun (such as arrhythmia, absence of rhythm). Before a vowel or h it becomes an- (as in anhydrous, anoxia).
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
American Heritage
Abbreviations & Acronyms
a
absent
A
  1. accusative

  2. ace

  3. across

  4. adenine

  5. alto

  6. American Stock Exchange

  7. ammeter

  8. ampere

  9. angstrom

  10. area

  11. Asian (as in personal ads)

  12. Baseball assist

  13. Austria (international vehicle ID)

a.
  1. acre

  2. adjective

  3. Latin anno (in the year)

  4. Latin annus (year)

  5. anode

  6. answer

  7. Latin ante (before)

  8. anterior

  9. artery

The American Heritage® Abbreviations Dictionary, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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Easton
Bible Dictionary

A definition


Alpha, the first letter of the Greek alphabet, as Omega is the last. These letters occur in the text of Rev. 1:8,11; 21:6; 22:13, and are represented by "Alpha" and "Omega" respectively (omitted in R.V., 1:11). They mean "the first and last." (Comp. Heb. 12:2; Isa. 41:4; 44:6; Rev. 1:11,17; 2:8.) In the symbols of the early Christian Church these two letters are frequently combined with the cross or with Christ's monogram to denote his divinity.

Easton's 1897 Bible Dictionary
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