合口呼 hékǒuhū closed-mouth sounds Origin Definitions Defs Strokes Stroke Words Sentences Sents 合口 hékǒu u-class final (bound form) refers to the 合口呼 hékǒuhū category in Chinese phonology, where the syllable has a "u" or "w" sound呼 hū phonological medial (of Chinese phonology) one of the four classes of syllable onsets or medials (四呼 sìhū)