The Collaborative International Dictionary of English v.0.48:

Peirastic \Pei*ras"tic\ (p[-i]*r[a^]s"t[i^]k), a. [Gr.
   peirastiko`s, fr. peira^n to try, fr. pei^ra a trial.]
   Fitted for trial or test; experimental; tentative; treating
   of attempts.
   [1913 Webster]