noun, na-adjective
self-willed; doing as one pleases; inconsiderate
Describes a person or behavior that is selfishly willful, acting without regard for others' convenience or feelings. Often used critically.
彼は勝手気ままに振る舞って、周りの迷惑を考えない。
He behaves as he pleases, without considering the trouble he causes others.
I like traveling alone, doing whatever I want.