In a contract, the Vendor refers to the seller.
Duhaime Legal Dictionary
The seller; the person selling.
Lect Law Library
A seller. One who disposes of a thing in consideration of money.
The Free (Legal) Dictionary
Seller; an individual who transfers property for sale; merchant; retail dealer; supplier.
The term vendor is frequently used in reference to an individual who sells real property.
A vendor, or a supplier, is a supply chain management term meaning anyone who provides goods or services to a company. A vendor often manufactures inventoriable items, and sells those items to a customer.