同意 means 'to agree' — it expresses acceptance or consent to a proposal, suggestion, plan, or request. The character 同 (tóng) means 'same' or 'together', and 意 (yì) means 'idea', 'intention', or 'will'. Together, they literally convey the idea of 'sharing the same intention' — aligning one’s will with another’s. It is commonly used in formal and informal contexts, such as workplace discussions, daily conversations, or written agreements.

This verb typically follows the subject and precedes the object (e.g., a clause introduced by 'that', often implied or marked by 的 or a full sentence). It can stand alone ('I agree') or take a noun phrase ('agree to the plan'), a verb phrase ('agree to help'), or a full clause ('agree that it’s necessary'). While it carries neutral-to-formal register, it’s less emphatic than 赞成 (zàn chéng) and more decisive than 好吧 (hǎo ba, 'okay').