Definition of unkind :
1. Having no race or kindred; childless.
2. Not kind; contrary to nature, or the law of kind or kindred; unnatural.
3. Wanting in kindness, sympathy, benevolence, gratitude, or the like; cruel; harsh; unjust; ungrateful.
brutal, edged, remorseless, hard, monstrous, stinging, sadistic, rude, barbarous, severe, cruel, savage, awful, evil, pitiless, hurtful, spiteful, malicious, unsympathetic, unkindly, ruffianly, ruthless, rigorous, unpitying, inhuman, hateful, inhumane, uncharitable, heartless, mean, malignant, cutting, malevolent, harsh