Wordnet 3.0
NOUN (1)
1. 
 goods or money obtained illegally; 
[syn: loot, booty, pillage, plunder, prize, swag, dirty money]
WordNet (r) 3.0 (2006):
dirty money
    n 1: goods or money obtained illegally [syn: loot, booty,
         pillage, plunder, prize, swag, dirty money]