Wordnet 3.0
ADJECTIVE (1)
1. 
 of or relating to the philosophical doctrine of monism; 
- Example: "the monistic school would regard national law and international law as an integrated whole"- J.S.Roucek
The Collaborative International Dictionary of English v.0.48:
Monistic \Mo*nis"tic\, a.
   Of, pertaining to, or involving, monism.
   [1913 Webster]
WordNet (r) 3.0 (2006):
monistic
    adj 1: 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