pet·u·lant 
(pĕchə-lənt)
(pĕchə-lənt)adj.
1. Unreasonably irritable or ill-tempered; peevish.
2. Contemptuous in speech or behavior.
[Latin petulāns, petulant-, insolent, from petere, to assail; see pet- in the Appendix of Indo-European roots.]
petu·lance, petu·lan·cy n.
petu·lant·ly adv.