The Collaborative International Dictionary of English v.0.48:

intrauterine device \in`tra*u"ter*ine de*vice"\, n.
   A contraceptive device consisting of a small, usually plastic
   object placed within the uterus to prevent conception; also
   called IUD.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

IUD \IUD\, n.
   An intrauterine device, a contraceptive device consisting
   of a small, usually plastic object placed within the uterus
   to prevent conception.
   [PJC]

WordNet (r) 3.0 (2006):

IUD
    n 1: contraceptive device consisting of a piece of bent plastic
         or metal that is inserted through the vagina into the
         uterus [syn: intrauterine device, IUD]