The Collaborative International Dictionary of English v.0.48:

downcast \down"cast`\, a.
   Cast downward; directed to the ground, from bashfulness,
   modesty, dejection, or guilt.
   [1913 Webster]

         'T is love, said she; and then my downcast eyes,
         And guilty dumbness, witnessed my surprise. --Dryden.

   2. depressed; dispirited; dejected; -- of people.

   Syn: down(predicate), downhearted, low, low-spirited.
        [WordNet 1.5] -- Down"cast`ly, adv. --
        Down"cast`ness, n.
        [1913 Webster]