Source : Webster's Revised Unabridged Dictionary (1913)

Flinty \Flint"y\, a. [Compar. {Flintier}; superl. {Flintiest}.]
   Consisting of, composed of, abounding in, or resembling,
   flint; as, a flinty rock; flinty ground; a flinty heart.

   {Flinty rock}, or {Flinty state}, a siliceous slate; --
      basanite is here included. See {Basanite}.

Source : WordNet®

flinty
     adj 1: showing unfeeling resistance to tender feelings; "the
            child's misery would move even the most obdurate
            heart" [syn: {obdurate}, {stony}]
     2: having austere inflexibility; "a flinty manner"; "granitic
        morality"; "his unyielding mouth and glassy eyes"-
        Marchette Chute [syn: {granitic}, {unyielding}]
     [also: {flintiest}, {flintier}]