费尽心思 fèijìnxīnsi to rack one's brains Origin Definitions Defs Strokes Stroke Words Sentences Sents 费 費 fèi verb to exert to use or consume effort, time, or energy尽 盡 jìn verb to use up to use up; to exhaust; to finish; to end心思 xīnsi mental effort mental energy or capacity for thinking, memory, and consideration; the intellectual effort put into a task