From WordNet (r) 3.0 (2006) [wn]:
vendor
n 1: someone who promotes or exchanges goods or services for
money [syn: seller, marketer, vender, vendor,
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]