muck

From Middle English mok, muk, from Old Norse myki, mykr (“dung”) or less likely Old English *moc, *moce (in hlōsmoc (“pigsty dung”) and lustmoce (“lady's smock (Cardamine pratensis)”)) (compare Icelandic mykja and Danish møg ("dung")), from Proto-Germanic *mukį̄ (“dung; manure”), from Proto-Germanic *muk-, from Proto-Indo-European *(s)mewg-, *mewk- (“slick, slippery”) (compare Welsh mign (“swamp”), Latin mūcus (“snot”), mucere (“to be moldy or musty”), Latvian mukls (“swampy”), Albanian myk (“mould”), Ancient Greek μύξα (múxa, “mucus, lamp wick”), Ancient Greek μύκης (múkēs, “mushroom”), German Mauke (“mud fever”)), from *(s)mewg, mewk 'to slip'. More at meek.