Source : Webster's Revised Unabridged Dictionary (1913)

Monistic \Mo*nis"tic\, a.
   Of, pertaining to, or involving, monism.

Source : WordNet®

monistic
     adj : of or relating to the philosophical doctrine of monism; "the
           monistic school would regard national law and
           international law as an integrated whole"- J.S.Roucek