勞心

to work with one's brains / to rack one's brains / to worry

to toil / labor / laborer / to put sb to trouble (of doing sth) / meritorious deed / to console (Taiwan pr. [lao4] for this sense)

heart / mind / intention / center / core / CL:顆|颗[ke1],個|个[ge4]

to tax one's mind and body / demanding (work) / dedicated (worker) / hard-working

to rack one's brains / to think hard