The story
- Anglo-Normanmarchaundise
- Latinmercātus
- Vulgar Latin*mercātāntem
- Old Frenchmarcheant
- Old Frenchmarcheandise
- Middle Englishmarchaundise
- Middle Englishmarchaundisen
- Englishmerchandise
- English todaymerchandisable
From merchandise + -able.
Etymology from Wiktionary, CC BY-SA 4.0.