Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
mercātor, ōris, m. [mercor], a trader, merchant, esp. a wholesale dealer (opp. to caupo, a retailer; class.). 
- I.  Lit.: venalicii mercatoresque, Cic. Or. 70, 232: multi ad eos mercatores ventitant, Caes. B. G. 4, 3. 
 
- II.  Transf. 
 
- A.  A dealer, speculator: non consules, sed mercatores provinciarum, Cic. post Red. in Sen. 4, 10.
Rarely of a petty dealer: vilis sacci mercator olentis, Juv. 14, 269. 
- B.  A buyer, purchaser: signorum, Cic. Verr. 1, 20, 60: veneni, Juv. 13, 154.