Source : Webster's Revised Unabridged Dictionary (1913)

Nugatory \Nu"ga*to*ry\, a. [L. nugatorius, fr. nugari to trifle,
   nugae jests, trifles.]
   1. Trifling; vain; futile; insignificant.

   2. Of no force; inoperative; ineffectual.

            If all are pardoned, and pardoned as a mere act of
            clemency, the very substance of government is made
            nugatory.                             --I. Taylor.

Source : WordNet®

nugatory
     adj : of no real value; "a nugatory law"