Source : Webster's Revised Unabridged Dictionary (1913)

Thirsty \Thirst"y\, a. [Compar. {Thirstier}; superl.
   {Thirstiest}.] [AS. [thorn]urstig. See {Thirst}, n.]
   1. Feeling thirst; having a painful or distressing sensation
      from want of drink; hence, having an eager desire.

            Give me, I pray thee, a little water to drink, for I
            am thirsty.                           --Judges iv.
                                                  19.

   2. Deficient in moisture; dry; parched.

            A dry and thirsty land, where no water is. --Ps.
                                                  lxiii. 1.

            When in the sultry glebe I faint, Or on the thirsty
            mountain pant.                        --Addison.

Source : WordNet®

thirsty
     adj 1: needing moisture; "thirsty fields under a rainless sky"
     2: feeling a need or desire to drink; "after playing hard the
        children were thirsty" [ant: {hungry}]
     3: (usually followed by `for') extremely desirous; "athirst for
        knowledge"; "hungry for recognition"; "thirsty for
        informaton" [syn: {athirst(p)}, {hungry(p)}, {thirsty(p)}]
     4: able to take in large quantities of moisture; "thirsty
        towels"
     [also: {thirstiest}, {thirstier}]

thirstiest
     See {thirsty}