What is the origin of moil?
English moil has a number of odd relatives. Middle English mollen “to moisten, soften by wetting” comes from Anglo-French moiller, muiller (Old French moiler “to soak, wet, stain”), from Vulgar Latin molliāre (from Latin mollīre “to soften, relax”), a derivative of mollis “soft, yielding to the touch.” From mollīre Latin derives ēmollīre “to soften, relax, soothe, enervate” (source of English emollient). Late Latin has mollificāre “to soften,” which via Middle French mollifier becomes English mollify. Students of French will recognize the French phonetics term mouillé “palatalized,” literally “wet, moistened.” In Spanish molliāre becomes mojar “to wet, moisten,” whose past participle mojado “wet, moistened” is familiar to many people from the phrase piso mojado “wet floor.” One of the senses of moil “to work hard” dates from the 16th century and is most likely a development of the sense “to make oneself wet, wallow in mire.” The Middle English verb mollen, mullen is the source of the uncommon verb mull, a metallurgical term meaning “to mix clay with sand (to make a mold).” Have we toiled and moiled on the topic enough for today? Moil entered English in the 15th century.