na-adjective, noun
calm; unconcerned; unfazed
Describes a person who remains composed, untroubled, or indifferent in a situation where others might worry. Often used in the negative to say one is not okay with something.
彼は試験の前でも平気な顔をしている。
He looks completely unfazed even before the exam.
I'm not okay with his rude attitude.
na-adjective
Colloquial use to say that something is acceptable, not a problem, or that one doesn't mind. Often used in questions and responses about permission or well-being.
「ここに座っても平気？」「うん、平気だよ。」
"Is it okay if I sit here?" "Yeah, it's fine."
もう痛みは平気ですか。
Is the pain all right now?