The Collaborative International Dictionary of English v.0.48:

Oversupply \O"ver*sup*ply`\, n.
   An excessive supply; a supply in excess of demand.
   [1913 Webster]

         A general oversupply or excess of all commodities. --J.
                                                  S. Mill.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Oversupply \O`ver*sup*ply"\, v. t.
   To supply in excess.
   [1913 Webster]

WordNet (r) 3.0 (2006):

oversupply
    n 1: the quality of being so overabundant that prices fall [syn:
         glut, oversupply, surfeit]
    v 1: supply with an excess of; "flood the market with tennis
         shoes"; "Glut the country with cheap imports from the
         Orient" [syn: flood, oversupply, glut]