涂改 (tú gǎi) is a verb meaning 'to alter' or 'to tamper with'—especially written or printed material such as documents, forms, or official records. The character 涂 (tú) originally means 'to smear' or 'to daub', suggesting covering or obscuring something; 改 (gǎi) means 'to change' or 'to revise'. Together, they convey the idea of physically altering text—often by erasing, crossing out, or overwriting—typically in a way that’s unauthorized or improper. It carries a slightly negative connotation, implying lack of permission or violation of procedure.

This word is commonly used in administrative, educational, and legal contexts—for example, when someone modifies grades on a report card, changes dates on a contract, or alters information on an application form. It differs from neutral revision terms like 修改 (xiūgǎi) because 涂改 emphasizes visible, manual alteration, often with questionable intent. It’s rarely used for digital edits or authorized revisions.