Moil may mean "to work hard" but its origins are the opposite of hard; it ultimately derives from Latin mollis, meaning "soft." (Other English derivatives of mollis are emollient, mollify, and mollusk.) A more immediate ancestor of moil is the Anglo-French verb moiller, meaning "to make wet, dampen," and one of the early meanings of moil in English was "to become wet and muddy." The "work hard" sense of moil appears most frequently in the pairing "toil and moil." Both moil and toil can also be nouns meaning "work." Moil implies work that is drudgery and toil suggests prolonged and fatiguing labor.
Examples of moil in a Sentence
Verb
miners moiling all day in the sunless recesses of the earth
the angry mob moiled around the courthouse
Noun
went for a retreat at the monastery for a temporary respite from the moil of the modern world
fed up with the moil and moneygrubbing of Wall Street, he decided to open a bed-and-breakfast in Vermont