Merriam-Webster's Collegiate® Dictionary, 11th Edition
CROCK
I. noun
Etymology: Middle English, from Old English crocc; akin to Old English crūce pot, pitcher, Middle High German krūche Date: before 12th century a thick earthenware pot or jar, soot , smut , coloring matter that rubs off from cloth or dyed leather, bunkum ,
II. verb
Date: 1594
transitive verb to put or preserve in a crock, to soil with crock ; smudge , intransitive verb to transfer color (as when rubbed or washed) ,
III. noun
Etymology: Middle English crok; akin to Low German krakke broken-down horse
Date: 1528
one that is broken-down, disabled, or impaired , a complaining medical patient whose illness is largely imaginary or psychosomatic,
IV. verb
Date: 1839
transitive verb to cause to become disabled, intransitive verb break down