Wordnet 3.0
NOUN (2)
1. 
 the largest of the Volcano Islands of Japan; 
2. 
 a bloody and prolonged operation on the island of Iwo Jima in which American marines landed and defeated Japanese defenders (February and March 1945); 
[syn: Iwo, Iwo Jima, invasion of Iwo]
WordNet (r) 3.0 (2006):
Iwo Jima
    n 1: the largest of the Volcano Islands of Japan
    2: a bloody and prolonged operation on the island of Iwo Jima in
       which American marines landed and defeated Japanese defenders
       (February and March 1945) [syn: Iwo, Iwo Jima, invasion
       of Iwo]