The Collaborative International Dictionary of English v.0.48:

Merchantable \Mer"chant*a*ble\, a.
   Fit for market; such as is usually sold in market, or such as
   will bring the ordinary price; as, merchantable wheat;
   sometimes, a technical designation for a particular kind or
   class.
   [1913 Webster]

WordNet (r) 3.0 (2006):

merchantable
    adj 1: fit to be offered for sale; "marketable produce" [syn:
           marketable, merchantable, sellable, vendable,
           vendible]