Verbs

(v)labor, labour, toil, fag, travail, grind, drudge, dig, moilwork hard“She was digging away at her math homework”, “Lexicographers drudge all day long”
(v)churn, boil, moil, roilbe agitated“the sea was churning in the storm”
(v)moilmoisten or soil“Her tears moiled the letter”