阐述 means 'to expound' or 'to elaborate' — to explain an idea, theory, or argument in a clear, detailed, and systematic way. The character 阐 (chǎn) means 'to open up, clarify, or reveal', while 述 (shù) means 'to state, narrate, or recount'. Together, they emphasize not just stating something, but developing it thoughtfully with supporting reasoning, evidence, or structure. This word is formal and commonly used in academic, professional, or official contexts — such as essays, speeches, policy documents, or scholarly presentations.

Unlike casual verbs like 说 (shuō, 'to say') or 讲 (jiǎng, 'to talk'), 阐述 implies depth, intentionality, and intellectual rigor. It often appears with abstract nouns like 观点 (guāndiǎn, 'viewpoint'), 理论 (lǐlùn, 'theory'), or 原则 (yuánzé, 'principle'). While it can be used in the first person ('I will elaborate...'), it's frequently found in third-person descriptions of others' explanations, especially in written Chinese.