挖空心思 wākōngxīnsi to rack one's brains Origin Definitions Defs Strokes Stroke Words Sentences Sents 挖 wā verb to dig to dig; to excavate; to hollow out the ground空 kōng adjective empty empty; hollow; void of content; containing nothing心思 xīnsi mental effort mental energy or capacity for thinking, memory, and consideration; the intellectual effort put into a task