乘虚 chéngxū to take advantage of a weakness Origin Definitions Defs Strokes Stroke Words Sentences Sents chéngxū to take advantage of a weakness 乘 chéng to take advantage of To avail oneself of an opportunity, circumstances, or someone's weakness.虚 虛 xū weak point a gap; a weak point; a vulnerabilitychéngxū to rise into the air 乘 chéng to mount (literary) to climb or ascend to a higher place虚 虛 xū adjective void emptiness; the void; space