O

O ¹  ()

interj.

1. Used before the name of or a pronoun referring to a person or thing being formally addressed: "How can I put it to you, O you who prepare to travel with important matters on your mind?" Jo Durden-Smith.

2. Used to express surprise or strong emotion: "O how I laugh when I think of my vague indefinite riches" Henry David Thoreau.

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O ²

The symbol for the element oxygen.

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o or O  ()

n. pl. o's or O's also os or Os

1. The 15th letter of the modern English alphabet.

2. Any of the speech sounds represented by the letter o.

3. The 15th in a series.

4. Something shaped like the letter O.

5. O One of the four major blood groups in the ABO system. Individuals with this blood group have neither A nor B antigens on the surface of their red blood cells, and have both anti-A and anti-B antibodies in their blood serum.

6. A zero.

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O ¹

1. Chem oxygen

2. Old

3. same as nought

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O ²

interj

same as oh

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O

The symbol for oxygen.

Thesaurus

Noun	1.	O - a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust atomic number 8, oxygen chemical element, element - any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter liquid oxygen, LOX - a bluish translucent magnetic liquid obtained by compressing gaseous oxygen and then cooling it below its boiling point; used as an oxidizer in rocket propellants air - a mixture of gases (especially oxygen) required for breathing; the stuff that the wind consists of; "air pollution"; "a smell of chemicals in the air"; "open a window and let in some air"; "I need some fresh air" H2O, water - binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent gas - a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely ozone - a colorless gas (O3) soluble in alkalis and cold water; a strong oxidizing agent; can be produced by electric discharge in oxygen or by the action of ultraviolet radiation on oxygen in the stratosphere (where it acts as a screen for ultraviolet radiation)
	2.	o - the 15th letter of the Roman alphabet Latin alphabet, Roman alphabet - the alphabet evolved by the ancient Romans which serves for writing most of the languages of western Europe alphabetic character, letter of the alphabet, letter - the conventional characters of the alphabet used to represent speech; "his grandmother taught him his letters"
	3.	O - the blood group whose red cells carry neither the A nor B antigens; "people with type O blood are universal donors" group O, type O blood group, blood type - human blood cells (usually just the red blood cells) that have the same antigens

Translations

O, o [əu] (letter) → O, o f;

O for Oliver (US);

O for Oboe → O de Oviedo

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O, o [əu] n (= letter) → O, o m;

(US) (Scol) (= outstanding) → tb (très bien);

O for Oliver (US);

O for Oboe → O comme Oscar

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O, o [əu] n (letter) → O nt, o nt;

(US) (Scol) (outstanding) → Eins f;

(Tel etc) → Null f;

O for Olive, O for Oboe (US) → O wie Otto

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O, o [əu] n (letter) → O, o f or m inv;

(US ) (SCOL) (= outstanding) → ottimo;

(number) (TEL etc) → zero;

O for Oliver (US);

O for Oboe → O come Otranto