Chinese idiom · 成语
口若悬河
Meaning
A mouth like a gushing river; eloquent speech.
Character by character
Origin and story
historicalThe Shishuo Xinyu (世说新语), in its section of appreciations, preserves Wang Yan's praise of Guo Xiang, whose courtesy name was Zixuan. Guo's discussion, he says, resembled water pouring from an elevated river: it flowed on without running dry. A parallel account in the Book of Jin (晋书) places the same praise in Guo Xiang's biography.
The metaphor became 口若悬河, a mouth like that inexhaustible stream. It emphasizes fluent, sustained speech and skill in argument. The original judgment is admiring, but later contexts can suggest someone who talks at great length. Eloquence alone does not guarantee that the speaker's claims are sound; the idiom describes the delivery, not the truth of every statement.
Sources and further reading
In everyday life
一谈到家乡的美食，他就口若悬河，连菜单上的小菜都能讲半天。
Once he starts on his hometown's food, the words pour out; he can talk for ages even about the side dishes.
Can admire fluency or gently suggest excessive talking; context sets the tone.