Someone who is petulant is unreasonably angry and upset in a childish way. His critics say he's just being silly and petulant + petulantly petu·lant·ly `I don't need help,' he said petulantly. behaving in an unreasonably impatient and angry way, like a child (from petere; PETITION)
[ -l&nt ] (adjective.) 1605. L or Middle French; Middle French, from Latin petulant-, petulans; akin to Latin petere to go to, attack, seek; more at FEATHER.