adverb
reproachfully; resentfully; with a grudge
Describes looking, speaking, or behaving in a way that shows resentment or a sense of being wronged. Often used with verbs like 見る or 言う.
彼女は恨めし気に私を見つめた。
She stared at me reproachfully.
彼は恨めし気に「どうして教えてくれなかったの」と言った。
He said resentfully, 'Why didn't you tell me?'