slop

From Middle English slop, sloppe, slope, from Old English *slop (found in oferslop (“an outergarment, surplice”)). Cognate with Icelandic sloppur (“a long, loose gown”).

Probably from Middle English *sloppe (attested in plural form sloppes), representing Old English *sloppe (attested in cūsloppe), alternative form of Old English slyppe. Related to slip.

Alteration of ecilop, back slang for police.