推理 (tuī lǐ) literally combines 推 (‘to push’ or ‘to deduce’) and 理 (‘reason’, ‘principle’, or ‘logic’), suggesting the mental process of pushing forward from known facts to reach a logical conclusion. As a noun, it refers to the act or result of logical inference — the structured thinking used in problem-solving, detective work, scientific analysis, or medical diagnosis. As a verb, it means ‘to reason’ or ‘to deduce’.

This word appears frequently in academic, professional, and analytical contexts — for example, when doctors infer a diagnosis from symptoms, scientists interpret experimental data, or students solve math proofs. It emphasizes rigorous, evidence-based thinking rather than guesswork or intuition. While 推理 can describe everyday reasoning, it carries a formal, intellectual tone and is rarely used in casual chit-chat about personal opinions or feelings.