na-adjective, noun
willful; self-indulgent; as one pleases
Describes a person who acts on their own whims without considering others. Often used in the phrase 気随気まま (きずいきまま).
彼は気随な性格で、人の言うことを聞かない。
He has a willful personality and doesn't listen to what others say.
気随気ままに旅をするのが好きだ。
I like to travel as the mood takes me.
気まま also means doing as one pleases, but is more common and neutral. 気随 has a stronger nuance of willfulness and is often paired with 気まま in the set phrase 気随気まま.
わがまま is more explicitly selfish or demanding, while 気随 focuses on following one's own whims, sometimes without negative connotation.
Compound of 気 (き, 'spirit, mood') and 随 (ずい, 'follow, obey'). Literally 'following one's mood'.