The Collaborative International Dictionary of English v.0.48:

Piecework \Piece"work`\, n.
   Work done by the piece or job; work paid for at a rate based
   on the amount of work done, rather than on the time employed.
   [1913 Webster]

         The reaping was piecework, at so much per acre. --R.
                                                  Jefferies.
   [1913 Webster]

WordNet (r) 3.0 (2006):

piecework
    n 1: work paid for according to the quantity produced