The Collaborative International Dictionary of English v.0.48:

Canteen \Can*teen"\ (k[a^]n*t[=e]n"), n. [F. cantine bottle
   case, canteen (cf. Sp. & It. cantina cellar, bottle case),
   either contr. fr. It. canovettina, dim. of canova cellar, or,
   more likely, fr. OF. cant. corner, It. & Sp. canto. See 1st
   Cant.] (Mil.)
   1. A small vessel used by soldiers or hikers for carrying
      water, liquor, or other drink. [Written also cantine.]
      [1913 Webster]

   Note: In 1910 in the English service the canteen is made of
         wood and holds three pints; in the United States it is
         usually a tin flask.
         [1913 Webster]

   2. A chest containing culinary and other vessels for military
      officers in a garrison.
      [1913 Webster]

   3. The sutler's shop in a garrison.
      [1913 Webster]

   4. Hence: A store or small shop within a larger establishment
      where refreshments and sometimes other supplies are sold.
      At a military base the canteen may be as large as a
      general store; within a school or small company it may be
      only a small counter with very limited supplies, or a
      snack bar.
      [PJC]

   5. A temporary location where food is dispensed during an
      emergency.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Cantine \Can*tine"\, n.
   See Canteen.
   [1913 Webster]