The Collaborative International Dictionary of English v.0.48:

Cask \Cask\ (k[.a]sk), n. [Sp. casco potsherd, skull, helmet,
   prob. fr. cascar to break, fr. L. Quassure to break. Cf.
   Casque, Cass.]
   1. Same as Casque. [Obs.]
      [1913 Webster]

   2. A barrel-shaped vessel made of staves headings, and hoops,
      usually fitted together so as to hold liquids. It may be
      larger or smaller than a barrel.
      [1913 Webster]

   3. The quantity contained in a cask.
      [1913 Webster]

   4. A casket; a small box for jewels. [Obs.] --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cask \Cask\, v. t.
   To put into a cask.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cask
    n 1: the quantity a cask will hold [syn: cask, caskful]
    2: a cylindrical container that holds liquids [syn: barrel,
       cask]