ball-buster

[bawl-buhs-ter]

noun Slang: Vulgar.

an arduous, often unpleasant task.
a person who makes great demands on others; taskmaster.

Also called ball-break·er [bawl-brey-ker] /ˈbɔlˌbreɪ kər/.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019