os

noun, plural os·sa [os–uh] /ˈɒs ə/.

1. Anatomy, Zoology. a bone.

noun, plural o·ra [awr–uh, ohr–uh] /ˈɔr ə, ˈoʊr ə/.

1. Anatomy, Zoology. a mouth or orifice of the body.

noun, plural o·sar [oh-sahr] /ˈoʊ sɑr/.

1. Geology. an esker, especially when of great length.

1. Symbol, Chemistry. osmium.

1. Old Saxon.
2. Computers. operating system.

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

1. the fifteenth letter of the English alphabet, a vowel.
2. any spoken sound represented by the letter O or o, as in box, note, short, or love.
3. something having the shape of an O.
4. a written or printed representation of the letter O or o.
5. a device, as a printer’s type, for reproducing the letter O or o.

interjection

1. (used before a name in direct address, especially in solemn or poetic language, to lend earnestness to an appeal): Hear, O Israel!
2. (used as an expression of surprise, pain, annoyance, longing, gladness, etc.)

noun, plural O’s.

3. the exclamation “O.”

1. (of the calendar) Old Style.
2. out of stock.
3. (in banking) outstanding.

1. (of the calendar) Old Style.

1. (in prescriptions) the left eye.

1. Old Saxon.
2. Old School.
3. Old series.
4. (of the calendar) Old Style.
5. Also o.s. ordinary seaman.

noun plural ossa (ˈɒsə)

1. anatomy the technical name for bone

noun plural ora (ˈɔːrə)

1. anatomy zoology a mouth or mouthlike part or opening

noun plural osar (ˈəʊsɑː)

1. another name for esker

the chemical symbol for

1. osmium

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)

noun plural o’s, O’s or 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

abbreviation for

1. out of stock
2. banking outstanding

symbol for

1. chem oxygen
2. a human blood type of the ABO groupSee universal donor
3. logic a particular negative categorial proposition, such as some men are not married: often symbolized as SoPCompare A, E, I 2

abbreviation for

4. Australian slang offence

interjection

1. a variant spelling of oh
2. an exclamation introducing an invocation, entreaty, wish, etcO God!; O for the wings of a dove!

interjection of fear, surprise, admiration, etc.; see oh. blood type, 1926, originally “zero,” denoting absence of A and B agglutinogens.

1. The symbol for the elementosmium

abbr.

1. oculus sinister (left eye)

1. The symbol for osmium.

1. The symbol for oxygen.

Os

1. 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.