费尽心血 fèijìnxīnxuè 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心血 xīnxuè painstaking effort Metaphorical heart's blood; specifically, the great care, meticulous effort, or vital energy expended on a task or project