ball-buster
[ bawl-buhs-ter ]
/ ˈbɔlˌbʌs tər /
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/.