‘应允’ is a formal literary verb meaning 'to consent' or 'to agree', often used when someone grants a request or approves a proposal. It combines two characters: 应 (yìng), meaning 'to respond' or 'to comply', and 允 (yǔn), meaning 'to permit' or 'to allow'. Together, they convey the idea of giving affirmative, willing approval — not just passive acceptance, but an active, gracious agreement.

This word appears frequently in written Chinese, official correspondence, historical narratives, and formal speeches. It carries a respectful, somewhat solemn tone and implies authority or responsibility on the part of the person consenting — for example, a parent agreeing to a child’s request, a supervisor approving a plan, or a government body endorsing a proposal. It is rarely used in casual spoken conversation, where simpler terms like 同意 (tóngyì) or 答应 (dāying) are preferred.