Meaning

noun any animal or plant material used to fertilize land especially animal excreta usually with litter material

verb spread manure, as for fertilization

originFrom Middle English maynouren, manuren (“to supervise, toil”), borrowed from Anglo-Norman meinourer and Old French manovrer (whence also English maneuver, or in French manœuvrer) from Vulgar Latin *manuoperare (“work by hand”), from Latin manū (“by hand”) + operārī (“to work”). Displaced native (in the plural) Old English mes.

Etymology from Wiktionary, CC BY-SA 3.0