Source : Webster's Revised Unabridged Dictionary (1913)

Athirst \A*thirst"\, a. [OE. ofthurst, AS. ofpyrsted, p. p. of
   ofpyrstan; pref. of-, intensive + pyrstan to thirst. See
   {Thirst}.]
   1. Wanting drink; thirsty.

   2. Having a keen appetite or desire; eager; longing.
      ``Athirst for battle.'' --Cowper.

Source : WordNet®

athirst
     adj : (usually followed by `for') extremely desirous; "athirst for
           knowledge"; "hungry for recognition"; "thirsty for
           informaton" [syn: {athirst(p)}, {hungry(p)}, {thirsty(p)}]