Synonyms of unforgiving

1. unforgiving (vs. forgiving), revengeful, vindictive, vengeful: usage: unwilling or unable to forgive or show mercy; "a surly unforgiving old woman"
2. grim, inexorable, relentless, stern, unappeasable, unforgiving, unrelenting, implacable (vs. placable): usage: 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"