The Collaborative International Dictionary of English v.0.48:

Praxis \Prax"is\, n. [NL., fr. Gr. ?, fr. ? to do. See
   Practice.]
   1. Use; practice; especially, exercise or discipline for a
      specific purpose or object. "The praxis and theory of
      music." --Wood.
      [1913 Webster]

   2. An example or form of exercise, or a collection of such
      examples, for practice.
      [1913 Webster]

WordNet (r) 3.0 (2006):

praxis
    n 1: translating an idea into action; "a hard theory to put into
         practice"; "differences between theory and praxis of
         communism" [syn: practice, praxis]