The Collaborative International Dictionary of English v.0.48:

Booty \Boo"ty\, n. [Cf. Icel. b[=y]ti exchange, barter, Sw. byte
   barter, booty, Dan. bytte; akin to D. buit booty, G. beute,
   and fr. Icel. byta, Sw. byta, Dan. bytte, to distribute,
   exchange. The Scandinavian word was influenced in English by
   boot profit.]
   That which is seized by violence or obtained by robbery,
   especially collective spoil taken in war; plunder; pillage.
   --Milton.
   [1913 Webster]

   To play booty, to play dishonestly, with an intent to lose;
      to allow one's adversary to win at cards at first, in
      order to induce him to continue playing and victimize him
      afterwards. [Obs.] --L'Estrange.
      [1913 Webster]

WordNet (r) 3.0 (2006):

booty
    n 1: goods or money obtained illegally [syn: loot, booty,
         pillage, plunder, prize, swag, dirty money]