From WordNet (r) 2.0 (August 2003) [wn]:
vendor
n : someone who promotes or exchanges goods or services for
money [syn: seller, marketer, vender, trafficker]
From The Collaborative International Dictionary of English v.0.48 [gcide]: Vendor \Vend"or\ (v[e^]nd"[o^]r), n. [See Vender.] A vender; a seller; the correlative of vendee. [1913 Webster]