The Collaborative International Dictionary of English v.0.48:

Cooper \Coop"er\, v. t. [imp. & p. p. Coopered; p. pr. & vb.
   n. Coopering.]
   To do the work of a cooper upon; as, to cooper a cask or
   barrel.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Coopering \Coop"er*ing\, n.
   Work done by a cooper in making or repairing barrels, casks,
   etc.; the business of a cooper.
   [1913 Webster]