Definition: Constantly varied functionally movements preformed at a relatively high intensity.  CrossFit begins with a belief in fitness. The aim of CrossFit is to forge a broad, general and inclusive fitness to prepare us for the unexpected. Military, law enforcement and fire fighters to name a few train at CrossFit. 

We have sought to build a program that will best prepare trainees for any physical contingency.  After looking at all sport and physical tasks collectively, we asked what physical skills and adaptations would most universally lend themselves to performance advantage. Capacity culled from the intersection of all sports demands would quite logically lend itself well to all sport. In sum, our specialty is not specializing. 

Definition from www.crossfit.com, see more information here: http://www.crossfit.com/cf-info/what-is-crossfit.html