- 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.
- (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.)
- the exclamation “O.”
Origin of O
- the fifteenth in order or in a series.
- the Arabic cipher; zero.
- (sometimes lowercase) the medieval Roman numeral for 11.Compare Roman numerals.
- Physiology. a major blood group, usually enabling a person whose blood is of this type to donate blood to persons of group O, A, B, or AB and to receive blood from persons of group O.Compare ABO system.
- Chemistry. oxygen.
- Logic. particular negative.
- an abbreviated form of of, as in o'clock or will-o'-the-wisp.
- an abbreviated form of on.
Origin of o'
- a prefix meaning “descendant,” in Irish family names: O'Brien; O'Connor.
Origin of O'
- an abridgment of ortho-.
- variant of ob- before m: omission.
- variant of oo-: oidium.
Origin of o.1
- a suffix occurring as the final element in informal shortenings of nouns (ammo; combo; condo; limo; promo); -o also forms nouns, usually derogatory, for persons or things exemplifying or associated with that specified by the base noun or adjective (cheapo; pinko; sicko; weirdo; wino).
- a suffix occurring in colloquial noun or adjective derivatives, usually grammatically isolated, as in address: cheerio; kiddo; neato; righto.
Origin of -o
- the typical ending of the first element of compounds of Greek origin (as -i- is, in compounds of Latin origin), used regularly in forming new compounds with elements of Greek origin and often used in English as a connective irrespective of etymology: Franco-Italian; geography; seriocomic; speedometer.
Origin of -o-
- (in prescriptions) a pint.
Origin of O.1
- the 15th letter of the Greek alphabet (O, o).
- the vowel sound represented by this letter.
Origin of omicron
Related Words for oforce, dash, juice, intensity, initiative, go, endurance, liveliness, application, animation, fortitude, effectiveness, might, exertion, life, efficacy, fire, ardor, activity, efficiency
Examples from the Web for o
Contemporary Examples of o
Born in Connecticut in 1847, he had a long railroad career before coming to the B O in 1896.The Stacks: H.L. Mencken on the 1904 Baltimore Fire
October 4, 2014
O flower of Scotland When will we see your like again … we can still rise now And be the nation again.Scots Must Choose Heart or Head
September 18, 2014
O daughter of Babylon… Happy shall he be, that taketh and dasheth thy little ones against the stones.Up to a Point: Shrugging Our Way Back to War in Iraq
P. J. O’Rourke
August 16, 2014
He also sent an email to [Goldman] saying: ‘[O]ne day I hope I get the real reason why you are doing this to me.’Too Big to Jail: Confessions of a Goldman Sachs Brat
June 26, 2014
Brother Slavs, we are on the verge, “[O Father] who art…” is heard in our midst.Ukraine Separatists' Pro-Putin Raps
June 23, 2014
Historical Examples of o
Ambrose only exclaimed “O uncle, you must have been hard pressed.”The Armourer's Prentices
Charlotte M. Yonge
O my dear, how my mother's condescension distressed me at the time!
I could hold no longer; but threw myself at her feet: O my dearest Mamma!
But, O my dear, the single life is by far the most eligible to me: indeed it is.
O the words of kindness, all to be expressed in vain, that flowed from her lips!
- 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
- Australian slang offence
Word Origin for O
- a variant spelling of oh
- an exclamation introducing an invocation, entreaty, wish, etcO God!; O for the wings of a dove!
- short for ortho- (def. 4)
- informal, or archaic shortened form of of a cup o' tea
- forming informal and slang variants and abbreviations, esp of nounswino; lie doggo; Jacko
Word Origin for -o
- the 15th letter in the Greek alphabet (Ο, ο), a short vowel, transliterated as o
Word Origin for omicron
- used to connect elements in a compound wordchromosome; filmography Compare -i-
Word Origin for -o-
Word Origin and History for o
interjection of fear, surprise, admiration, etc.; see oh.
blood type, 1926, originally "zero," denoting absence of A and B agglutinogens.
as a prefix in Irish names, from Irish ó, ua (Old Irish au) "descendant."
15th letter of the Greek alphabet, literally "small 'o,' " from Greek (s)mikros "small," from PIE *smik-. Because the vowel was "short" in ancient Greek. Cf. Omega.
- ortho- (often italic)
- Used as a connective to join word elements:acidophilic.
- The 15th letter of the Greek alphabet.
- The symbol for oxygen.
- 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 -218.8°C; boiling point -182.9°C; gas density at 0°C 1.429 grams per liter; valence 2. See Periodic Table.
Word History: 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.