Moil

Definition:

(v. t.) To daub; to make dirty; to soil; to defile.
(v. i.) To soil one's self with severe labor; to work with painful effort; to labor; to toil; to drudge.
(n.) A spot; a defilement.

Compare moil with other words:

drudgery vs. moil

labour vs. moil

moil vs. turmoil