noun, na-adjective, noun which may take the genitive case particle 'no'
irritability; peevishness; hot temper
Describes a personality trait or temporary state of being easily annoyed, quick to anger, or touchy. Often used with な or の to modify nouns.
彼は癇性で、ちょっとしたことですぐ怒る。
He is irritable and gets angry at the slightest thing.
癇性な性格を直したい。
I want to fix my irritable personality.
Composed of 癇 (かん, 'nervousness' or 'irritability') and 性 (しょう, 'nature' or 'temperament'). The exact historical derivation is uncertain, but the combination directly conveys a temperament prone to irritation.