The story
- Old English · inherited fromoferslop
- Middle English · inherited fromoversloppe
- English todayoverslop
From Middle English oversloppe, Old English oferslop, oferslype (“an overgarment; surplice”), equivalent to over- + slop. Cognate with Icelandic yfirsloppur (“overalls”).
Etymology from Wiktionary, CC BY-SA 4.0.