na-adjective, noun which may take the genitive case particle 'no', noun
unruly; disobedient; strong-willed
Describes a person, especially a child, who is stubborn, refuses to listen, and has a strong independent streak. Often used in the phrase きかん気が強い.
うちの子はきかん気で、言うことをなかなか聞かない。
Our child is strong-willed and rarely does as told.
彼はきかん気が強くて、自分の意見を曲げない。
He is very headstrong and never bends his opinions.
The word combines きかん (likely from 利かん or 聞かん, negative forms implying 'not effective' or 'not listening') with 気 (spirit/temperament). The exact derivation is uncertain, but it has come to mean a stubborn, unyielding disposition.