Source : WordNet®

unforgiving
     adj 1: unwilling or unable to forgive or show mercy; "a surly
            unforgiving old woman" [ant: {forgiving}]
     2: not to be placated or appeased or moved by entreaty; "grim
        determination"; "grim necessity"; "Russia's final hour, it
        seemed, approached with inexorable certainty"; "relentless
        persecution"; "the stern demands of parenthood" [syn: {grim},
         {inexorable}, {relentless}, {stern}, {unappeasable}, {unrelenting}]
     3: harsh and severe; "I hope I'm not being uncharitable but he
        really is a bore"; "unjust and uncharitable criticism"
        [syn: {uncharitable}]