n 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.
n (printing) w:American Library Association | American Library Association (non-gloss definition|(abbreviation) of octavo, a book size (20-25 cm).)
n (soccer) Someone associated with w:Leyton Orient Football Club | Leyton Orient Football Club, as a player, coach, supporter etc.
! (non-gloss definition|Expression of earnestness or reverence, used before the name of a deity or revered person in impassioned speech.)