大概 (dà gài) is an adverb meaning 'roughly', 'approximately', or 'more or less'. It expresses estimation or uncertainty about quantity, time, degree, or probability — never exact precision. The character 大 means 'big' or 'large', and 概 means 'general idea' or 'outline'; together, they convey the sense of a broad, inclusive approximation rather than a detailed calculation.

This word is commonly used in everyday speech and writing when giving round numbers, vague timeframes, or tentative conclusions — for example, estimating how long something takes, how many people attended, or how likely something is. It often appears before verbs, adjectives, or numerals, and may soften statements to sound more polite or cautious. Unlike precise quantifiers like 确切地 (quèqiè de), 大概 signals intentional imprecision, making it useful for hedging claims or avoiding overcommitment.