- headwork
- nthought, hard thought, brainwork, using one's little gray cells; beating or cudgeling one's brains out; cogitation, meditation, contemplation, mulling, pondering; concentration, reasoning, ratiocination, analysis, deduction, problem-solving, riddle-solving, planning; study, homework, hitting the books, burning the midnight oil, lucubration, Inf. pulling an all-nighter, cramming, memorizing; exercising one's brain, mental workout, mental calisthenics.
A Note on the Style of the synonym finder. 2014.