o

Short definition from Wiktionary

Character

1. 1
   The fifteenth letter of the English alphabet, called o and written in the Latin script.
2. 2
   Alternative form of ο, the fifteenth letter of the Classical and Modern Greek alphabets, called omicron and (astronomy) used as an abbreviation of omicron in star names.
3. 3
   The fifteenth letter of the English alphabet, called o and written in the Latin script.

Numeral

1. 1
   The ordinal number fifteenth, derived from this letter of the English alphabet, called o and written in the Latin script.
2. 2
   The ordinal number fifteenth, derived from this letter of the English alphabet, called o and written in the Latin script.

Noun

1. 1
   The name of the Latin-script letter O/o.
2. 2
   A zero (used in reading out numbers).
3. 3
   Operator
4. 4
   Object, see SVO
5. 5
   Something shaped like the letter O.
6. 6
   A blood type that lacks A or B antigens and may only receive transfusions of similar type O blood, but may donate to all (neglecting Rh factor). Synonym: universal donor.
7. 7
   An utterance of the vocative O.
8. 8
   American Library Association abbreviation of octavo, a book size (20-25 cm).
9. 9
   Someone associated with Leyton Orient Football Club, as a player, coach, supporter etc.
10. 10
    The number of overs bowled.
11. 11
    Orgasm.
12. 12
    Opium.

Particle

1. 1
   alternative form of O (vocative particle)
2. 2
   The vocative particle, used for direct address.

Interjection

1. 1
   Alternative form of oh.

Adjective

1. 1
   Clipping of over.
2. 2
   Abbreviation of morally offensive, film classification of the National Legion of Decency.
3. 3
   Abbreviation of Orthodox.
4. 4
   With sugar and no condensed milk added.

Preposition

1. 1
   Alternative form of of.
2. 2
   Abbreviation of out, letter/sound sequence out.

Proper noun

1. 1
   A surname from Korean.
2. 2
   A surname from Mandarin Chinese.
3. 3
   Alternative form of E (Ancient Chinese Kingdom)

Symbol

1. 1
   Chemical symbol for oxygen.
2. 2
   big O: a class of functions asymptotically bounded from above by a specific function, up to a constant factor