o

noun11

1. •
   A zero (used in reading out numbers).

   • It is currently two-o-five in the afternoon (2:05 PM).
   • The first permanent English settlement in America was in Jamestown in sixteen-o-seven (1607).
2. •
   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.
3. •
   Something shaped like the letter O.
4. •
   (slang) Orgasm.

   • Further on, when she's about to reach her first O, the taste turns from no taste to champagne-like. — 1999
5. •
   An utterance of the vocative O.
6. •
   Object, see SVO
7. •
   (Internet) Operator
8. •
   (slang) Opium.

   • We lay on our stomachs on the living-room floor in a circle around our host, a skinny little man who said he'd been smoking O for 20 years. — 1952
9. •
   The number of overs bowled.
10. •
    Someone associated with Leyton Orient Football Club, as a player, coach, supporter etc.
11. •
    American Library Association abbreviation of octavo, a book size (20-25 cm).

adjective4

1. •
   (Singapore, informal) With sugar and no condensed milk added.

   • Better try their kopi-o tarik. Our version nowadays taste like cough medicine. LOL! — 2003
2. •
   (Judaism) Abbreviation of Orthodox.
3. •
   Clipping of over.
4. •
   (historical) Abbreviation of morally offensive, film classification of the National Legion of Decency.

O particle1

1. •
   The vocative particle, used for direct address.

   • O Death! O Death! Won't you spare me over till another year? - part of the refrain from the American folk song "A Conversation with Death".

noun1

1. •
   A blood type that has no antigens. It lacks the A, B and Rh factors on the blood cells. It is the universal donor for blood and can give blood to any blood type, but can only receive O- blood.