Source : Webster's Revised Unabridged Dictionary (1913)

Inappropriate \In`ap*pro"pri*ate\, a.
   Not instrument (to); not appropriate; unbecoming; unsuitable;
   not specially fitted; -- followed by to or for. --
   {In`ap*pro"pri*ate*ly}, adv. -- {In`ap*pro"pri*ate*ness}, n.

Source : WordNet®

inappropriateness
     n 1: inappropriate conduct [syn: {wrongness}] [ant: {appropriateness}]
     2: the quality of not being particularly suitable [ant: {appropriateness}]