'Tōngshùn' describes language that flows naturally and logically—neither awkward nor confusing. Literally, 'tōng' means 'to pass through' or 'unimpeded', and 'shùn' means 'smooth' or 'in order'; together they evoke the image of speech or writing moving effortlessly from beginning to end. It’s most often used to evaluate written or spoken Chinese for clarity, logical progression, and natural phrasing—not just grammatical correctness.

This word is common in academic, editorial, and language-learning contexts: teachers praise students’ essays as 'tōngshùn', editors mark revisions to improve 'tōngshùn', and learners are reminded that vocabulary and grammar alone aren’t enough—ideas must connect smoothly. While it can occasionally describe physical movement (e.g., traffic flow), its primary and overwhelmingly dominant use is linguistic: fluent, coherent, well-structured expression.