The story
- Old English · inherited fromscotfrēo“scot-free; exempt from royal tax or imposts”
- Middle English · inherited fromscotfre
- English todayscot-free
From Middle English scotfre, from Old English scotfrēo (“scot-free; exempt from royal tax or imposts”), equivalent to scot (“payment; contribution; fine”) + -free.
Etymology from Wiktionary, CC BY-SA 4.0.