grim

adjective

1. not to be placated or appeased or moved by entreaty"grim determination"
2. shockingly repellent; inspiring horror"ghastly wounds"
3. harshly ironic or sinister"black humor"
4. harshly uninviting or formidable in manner or appearance"a dour, self-sacrificing life"
5. filled with melancholy and despondency"gloomy at the thought of what he had to face"
6. causing dejection"a blue day"