The Collaborative International Dictionary of English v.0.48:

Monger \Mon"ger\, n. [AS. mangere, fr. mangian to trade; akin to
   Icel. manga to trade, mangari a trader, OHG. mangari,
   mengari; cf. L. mango a dealer in slaves.]
   1. A trader; a dealer; -- now used chiefly in composition;
      as, fishmonger, ironmonger, newsmonger.
      [1913 Webster]

   2. A small merchant vessel. [Obs.] --Blount.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Monger \Mon"ger\, v. t.
   To deal in; to make merchandise of; to traffic in; -- used
   chiefly of discreditable traffic.
   [1913 Webster]

WordNet (r) 3.0 (2006):

monger
    n 1: someone who purchases and maintains an inventory of goods
         to be sold [syn: trader, bargainer, dealer, monger]
    v 1: sell or offer for sale from place to place [syn: peddle,
         monger, huckster, hawk, vend, pitch]

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "monger":
   arab, chandler, dealer, distributor, duffer, hawk, hawker, higgler,
   huckster, importer, jobber, marketer, merchandiser, merchant,
   middleman, regrater, retail dealer, retail merchant, retailer,
   shopkeeper, storekeeper, trader, tradesman, tradeswoman,
   trafficker, vend, vendor, wholesaler