Emily Dickinson Lexicon

TASK-MAS-TER, n. [task and master.]

1. One who imposes a task, or burdens with labor. Sinful propensities and appetites are men's most unrelenting taskmasters. They condemn us to unceasing drudgery, and reward us with pain, remorse and poverty. Next to our sinful propensities, fashion is the most oppressive taskmaster.
2. One whose office is to assign tasks to others. Exod i. iii.