Source : Webster's Revised Unabridged Dictionary (1913)

Nonnatural \Non*nat"u*ral\, a.
   Not natural; unnatural.

Source : WordNet®

nonnatural
     adj : existing outside of or not in accordance with nature; "find
           transcendental motives for sublunary action"-Aldous
           Huxley [syn: {otherworldly}, {preternatural}, {transcendental}]