边擦音 biāncāyīn lateral fricative Definitions Defs Origin Strokes Stroke Words Sentences Sents 边 邊 biān noun side (geometry) side of a geometric shape; a line segment forming a polygon擦音 cāyīn fricative A consonant sound produced by forcing air through a narrow channel in the vocal tract; also called 摩擦音 mócāyīn.