na-adjective, noun
unruly; disobedient; strong-willed
Rare term describing a stubborn, unyielding disposition, often of a child. Compare with the more common きかん気.
See also: きかん気
あの子はきかぬ気で、言うことを聞かない。
That child is unruly and won't listen to what they're told.
彼のきかぬ気な態度には手を焼く。
His unyielding attitude is a handful.
More common synonym with the same meaning; きかぬ気 is a rarer variant.
Compound of きかぬ (negative form of きく, 'to be effective' or 'to listen') + 気 ('spirit, disposition'). The exact derivation is uncertain, but it likely arose as a variant of きかん気.