c. 1400, "mudhole," probably from Old English -sloppe "dung" (in plant name cusloppe, literally "cow dung"), related to slyppe "slime" (see slip (v.)). Meaning "semiliquid food" first recorded 1650s; that of "refuse liquid of any kind, household liquid waste" (usually slops) is from 1815. Meaning "affected or sentimental material" is from 1866.[slop etymology, slop origin, 英语词源]