The Collaborative International Dictionary of English v.0.48:
Misdemean \Mis`de*mean"\, v. t. To behave ill; -- with a reflexive pronoun; as, to misdemean one's self. [1913 Webster]WordNet (r) 3.0 (2006):
misdemean v 1: behave badly; "The children misbehaved all morning" [syn: misbehave, misconduct, misdemean] [ant: behave, comport]