What does 呑気 mean?
呑気 is a Japanese noun meaning “carefree, optimistic, careless” in English. It is written as 呑気 in kanji, のんき in hiragana, and nonki in romaji. This word is part of JLPT N2 vocabulary.
Example sentence
お前は当事者じゃないから、そんなのんきなこと言ってられるんだよ。
You wouldn't be so casual about it if you were directly involved.