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unwillingly; reluctantly; grudgingly
shaking one's head in refusal (like a child)
いやいやながら参加した会議が意外と有益だった。
The meeting I attended reluctantly turned out to be unexpectedly useful.
彼はいやいや頭を下げて謝罪の言葉を述べた。
He reluctantly bowed his head and offered words of apology.
いやいやでも続けるうちに楽しくなってきた。
Even though I did it reluctantly, it became enjoyable as I continued.