何気無く[なにげなく] (nanigenaku)

私わたしは何気無なにげなく彼かれの方ほうを見みた

I looked in his direction inadvertently.

何気無く言ったことが大問題になった

A casual remark I made caused a major problem.

僕が何気無く言ったことがたいそうお気に障った

He was highly offended at what I had said without any malice.

彼は何気無く言ったのだろうが僕はそれを聞いてギョッとした

I was startled by what he must have said casually.