moil \MOYL\ (intransitive verb) - 1 : To work with painful effort; to labor; to toil; to drudge. 2 : To churn or swirl about continuously.
(noun) - 1 : Toil; hard work; drudgery. 2 : Confusion; turmoil.
"Why should he toil and moil, and be at so much trouble to pick himself up out the mud, when, in a little while hence, the strong arm of his Uncle will raise and support him?" -- Nathaniel Hawthorne, "The Scarlet Letter"
Moil comes from Middle English moillen, "to soak, to wet," hence "to soil, to soil one's hands, to work very hard," from Old French moillier, "to soften, especially by making wet," ultimately from Latin mollis, "soft."