应允 (yīngyǔn): to give one's assent

Meanings

Fùqīn zhōngyú yīngyǔnle tā de qǐngqiú.

His father finally consented to his request.

Tā diǎn tóu yīngyǔn, biǎoshì yuànyì bāngmáng.

She nodded in assent, indicating she'd be glad to help.

register

Slightly formal, common in narrative and written Chinese. The everyday word is 答应 (dāying, to agree). Note: Taiwan often pronounces this yìngyǔn.

应 yīng

允 yǔn