答辩 (dá biàn) is a formal noun meaning 'oral defense' — most commonly referring to the spoken presentation and Q&A session required when defending an academic thesis or dissertation before a panel of professors. The character 答 means 'to answer' or 'to respond', while 辩 means 'to debate', 'to argue', or 'to defend a position logically'. Together, they convey the core idea of verbally responding to questions and defending one’s work through reasoned argument.

This term is used almost exclusively in academic and professional credentialing contexts in China and other Chinese-speaking regions — for example, undergraduate, master’s, or doctoral thesis defenses; also occasionally for major project presentations in research institutions or technical certification reviews. It carries strong connotations of formality, evaluation, and intellectual accountability, and is rarely used outside structured educational or institutional settings.