os

a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.

an extraordinary or unusual thing, person, or event; an exceptional example or instance.

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noun, plural o·sar

[oh-sahr] .

Geology. an esker, especially when of great length.

Origin:
< Swedish ås (plural åsar) ridge

Old Saxon.

Computers. operating system.

Symbol, Chemistry, osmium.

(of the calendar) Old Style.

out of stock.

(in banking) outstanding.

(in prescriptions) the left eye. Origin:
< Latin oculus sinister.

Old Saxon.

Old School.

Old series.

(of the calendar) Old Style.

ordinary seaman.

(in prescriptions) the left eye. Origin:
< Latin oculus sinister.

ordinary seaman.

noun, plural O's or Os; o's or os or oes.

the fifteenth letter of the English alphabet, a vowel.

any spoken sound represented by the letter O or o, as in box, note, short, or love .

something having the shape of an O .

a written or printed representation of the letter O or o.

a device, as a printer's type, for reproducing the letter O or o.

interjection

(used before a name in direct address, especially in solemn or poetic language, to lend earnestness to an appeal): Hear, O Israel!

(used as an expression of surprise, pain, annoyance, longing, gladness, etc.)

noun

the exclamation “O.”

Origin:
1125–75; Middle English < Old French < Latin ō

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2013.
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Link To os

Collins

World English Dictionary

o or O (əʊ)

—n , pl o's, O's, Os
1.	the 15th letter and fourth vowel of the modern English alphabet
2.	any of several speech sounds represented by this letter, in English as in code, pot, cow, move, or form
3.	another name for nought

O or O

—n

o or O (əʊ)

—n , pl o's, O's, Os
1.	the 15th letter and fourth vowel of the modern English alphabet
2.	any of several speech sounds represented by this letter, in English as in code, pot, cow, move, or form
3.	another name for nought

O or O

—n

O¹

—*symbol for*
1.	chem oxygen
2.	See universal donor a human blood type of the ABO group
3.	logic A E Compare I a particular negative categorial proposition, such as some men are not married: often symbolized as SoP

—*abbreviation for*
4.	slang (Austral) offence

[(for sense 3) from Latin (neg)o I deny]

O² (əʊ)

—*interj*
1.	a variant spelling of oh
2.	an exclamation introducing an invocation, entreaty, wish, etc: O God!; O for the wings of a dove!

o' (ə)

—*prep*
	informal, archaic or shortened form of of : a cup o' tea

os¹ (ɒs)

—n , pl ossa
	anatomy the technical name for bone

[C16: from Latin: bone; compare Greek osteon]

os² (ɒs)

—n , pl ora
	anatomy, zoology a mouth or mouthlike part or opening

[C18: from Latin]

os³ (əʊs)

—n , pl osar
	another name for esker

[C19 osar (pl), from Swedish ås (sing) ridge]

Os

—*the chemical symbol for*
	osmium

OS

—*abbreviation for*
1.	Old School
2.	Old Style (method of reckoning dates)
3.	Ordinary Seaman
4.	(in Britain) Ordnance Survey
5.	outsize
6.	Old Saxon (language)

o.s., OS or O/S

—*abbreviation for*
1.	out of stock
2.	banking outstanding

OS, OS or O/S

—*abbreviation for*

O/S, OS or O/S

—*abbreviation for*

o.s., OS or O/S

—*abbreviation for*
1.	out of stock
2.	banking outstanding

OS, OS or O/S

—*abbreviation for*

O/S, OS or O/S

—*abbreviation for*

o.s., OS or O/S

—*abbreviation for*
1.	out of stock
2.	banking outstanding

OS, OS or O/S

—*abbreviation for*

O/S, OS or O/S

—*abbreviation for*

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

interj. of fear, surprise, admiration, etc., see oh.

blood type, 1926, originally "zero," denoting absence of A and B agglutinogens.

Online Etymology Dictionary, © 2010 Douglas Harper
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American Heritage

Medical Dictionary

o
The Greek letter omicron. Entries beginning with this character are alphabetized under omicron.

O ¹

The symbol for the element oxygen.

O ²
abbr.
oculus

os ¹ (ŏs)
n. pl. o·ra (ôr'ə)

An opening into a hollow organ or canal.
The oral cavity; mouth.

os ² (ŏs)
n. pl. os·sa (ŏs'ə)
Bone.

Os
The symbol for the element osmium.

OS abbr.
Latin oculus sinister (left eye)

American Heritage

Science Dictionary

O
The symbol for oxygen.

Os
The symbol for osmium.

osmium

(ŏz'mē-əm) Pronunciation Key
Symbol Os
A hard, brittle, bluish-white metallic element that is the densest naturally occurring element. It is used to make very hard alloys for fountain pen points, electrical contacts, and instrument pivots. Atomic number 76; atomic weight 190.2; melting point 3,000°C; boiling point 5,000°C; specific gravity 22.57; valence 2, 3, 4, 8. See Periodic Table.

oxygen

(ŏk'sĭ-jən) Pronunciation Key
Symbol O
A nonmetallic element that exists in its free form as a colorless, odorless gas and makes up about 21 percent of the Earth's atmosphere. It is the most abundant element in the Earth's crust and occurs in many compounds, including water, carbon dioxide, and iron ore. Oxygen combines with most elements, is required for combustion, and is essential for life in most organisms. Atomic number 8; atomic weight 15.9994; melting point -218.4°C; boiling point -183.0°C; gas density at 0°C 1.429 grams per liter; valence 2. See Periodic Table.

Our Living Language : In 1786, the French chemist Antoine Lavoisier coined a term for the element oxygen (oxygène in French). He used Greek words for the coinage: oxy- means "sharp," and -gen means "producing." Oxygen was called the "sharp-producing" element because it was thought to be essential for making acids. Lavoisier also coined the name of the element hydrogen, the "water-producing" element, in 1788. Soon after, in 1791, another French chemist, J. A. Chaptal, introduced the word nitrogen, the "niter-producing" element, referring to its discovery from an analysis of nitric acid.

Slang Dictionary

/O-S/
1. [Operating System] n. An abbreviation heavily used in email, occasionally in speech.
2. n. obs. On ITS, an output spy. See "OS and JEDGAR" in Appendix A.

Jargon
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FOLDOC

Computing Dictionary

OS definition

1. operating system.
2. [obsolete, ITS], an output spy. See "OS and JEDGAR".
3. An operating system from IBM for their System/360 line of hardware announced in 1964. OS was planned with several flavours that were supposed to be compatible. OS was late, memory hungry and not able to reach the marketing objectives of IBM for the 360/30, the planned successor of the IBM 1401. IBM then decided to design a new operating system for the low end machines which they called DOS/360.
[Jargon File]
(1997-09-22)

American Heritage

Abbreviations & Acronyms

Latin octarius (pint)
octavo
ohm

old
Oriental (as in personal ads, but usually A, Asian)
out
outstanding

Os
osmium

offscreen
Old Saxon
Old Style (calendar)
operating system
ordinary seaman
out of stock

o.s.

Latin oculus sinister (left eye)
old series
out of stock

Encyclopedia Britannica

Encyclopedia

(Os), chemical element, one of the platinum metals of Group VIIIb of the periodic table and the densest naturally occurring element. A gray-white metal, osmium is very hard, brittle, and difficult to work, even at high temperatures. Of the platinum metals it has the highest melting point, so fusing and casting are difficult. Osmium wires were used for filaments of early incandescent lamps before the introduction of tungsten. It has been used chiefly as a hardener in alloys of the platinum metals, though ruthenium has generally replaced it. A hard alloy of osmium and iridium has been used for tips of fountain pens and phonograph needles, and osmium tetroxide is used in certain organic syntheses.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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