Wordnet 3.0
NOUN (1)
1. 
 a man who serves as a sailor; 
[syn: mariner, seaman, tar, Jack-tar, Jack, old salt, seafarer, gob, sea dog]
WordNet (r) 3.0 (2006):
Jack-tar
    n 1: a man who serves as a sailor [syn: mariner, seaman,
         tar, Jack-tar, Jack, old salt, seafarer, gob,
         sea dog]