French word vendeur comes from French vendre, French -eur

Detailed word origin of vendeur

Dictionary entry	Language	Definition
vendre	French (fra)	(reflexive) to sell. (transitive) to sell. (transitive) to sell out (betray).
-eur	French (fra)	Used to form abstract nouns from adjectives; -ness.. Used to form agent nouns from verbs.
vendeur	French (fra)	Salesman. Seller, vendor.

Words with the same origin as vendeur