crock (n.) Look up crock at Dictionary.com
Old English crocc, crocca "pot, vessel," from Proto-Germanic *krogu "pitcher, pot" (cognates: Old Frisian krocha "pot," Old Saxon kruka, Middle Dutch cruke, Dutch kruik, Old High German kruog "pitcher," German Krug, Old Norse krukka "pot"). Perhaps from the same source as Middle Irish crocan "pot," Greek krossos "pitcher," Old Church Slavonic krugla "cup." Used as an image of worthless rubbish since 19c., perhaps from the use of crockery as chamberpots.