The Collaborative International Dictionary of English v.0.48:

Spree \Spree\ (spr[=e]), n. [Cf. Ir. spre a spark, animation,
   spirit, Gael. spraic. Cf. Sprack.]
   A merry frolic; especially, a drinking frolic; a carousal.
   [Colloq.]
   [1913 Webster]

   spending spree an incident in which one spends money
      freely; -- usually designating indiscreet or reckless
      spending on unneeded items.
      [PJC]

WordNet (r) 3.0 (2006):

spending spree
    n 1: a brief period of extravagant spending