noun, plural os·sa [os–uh] /ˈɒs ə/.
- Anatomy, Zoology. a bone.
noun, plural o·ra [awr–uh, ohr–uh] /ˈɔr ə, ˈoʊr ə/.
- Anatomy, Zoology. a mouth or orifice of the body.
noun, plural o·sar [oh-sahr] /ˈoʊ sɑr/.
- Geology. an esker, especially when of great length.
- Symbol, Chemistry. osmium.
- Old Saxon.
- Computers. operating system.
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, plural O’s.
- the exclamation “O.”
- (of the calendar) Old Style.
- out of stock.
- (in banking) outstanding.
- (of the calendar) Old Style.
- (in prescriptions) the left eye.
- Old Saxon.
- Old School.
- Old series.
- (of the calendar) Old Style.
- Also o.s. ordinary seaman.
noun plural ossa (ˈɒsə)
- anatomy the technical name for bone
noun plural ora (ˈɔːrə)
- anatomy zoology a mouth or mouthlike part or opening
noun plural osar (ˈəʊsɑː)
- another name for esker
the chemical symbol for
- osmium
abbreviation for
- Old School
- Old Style (method of reckoning dates)
- Ordinary Seaman
- (in Britain) Ordnance Survey
- outsize
- Old Saxon (language)
noun plural o’s, O’s or Os
- the 15th letter and fourth vowel of the modern English alphabet
- any of several speech sounds represented by this letter, in English as in code, pot, cow, move, or form
- another name for nought
abbreviation for
- out of stock
- banking outstanding
symbol for
- chem oxygen
- a human blood type of the ABO groupSee universal donor
- logic a particular negative categorial proposition, such as some men are not married: often symbolized as SoPCompare A, E, I 2
abbreviation for
- Australian slang offence
interjection
- a variant spelling of oh
- 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.
- The symbol for the elementosmium
abbr.
- oculus sinister (left eye)
- The symbol for osmium.
- The symbol for oxygen.
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.