adverb, adverb taking the 'to' particle
pressingly; demandingly; naggingly
Mimetic adverb describing persistent, annoying urging or demanding, often with 言う or similar verbs. Used when someone keeps pressing another person to do something.
母は私に宿題をやいやい言った。
My mother kept nagging me about my homework.
彼はやいやいと返事を迫った。
He pressed me for an answer insistently.
interjection
Casual interjection used to call someone's attention, often with a slightly rough or impatient tone. Can be repeated for emphasis.
やいやい、そこで何をしているんだ？
Hey, what are you doing over there?
やいやい、待ちなよ！
Oi, wait up!
Mimetic word, likely derived from the sound of repeated calling or urging. The exact origin is uncertain.