WordNet sense 1 (sullen or moody):

huffish

WordNet sense 2 (having an irritable and unpleasant disposition):

ill-natured

WordNet sense 3 (with little movement; very slow):

sluggish

WordNet sense 4 (not moving quickly; taking a comparatively long time):

slow

WordNet sense 5 (depressingly dark):

gloomy, gloomful, glooming

WordNet sense 6 (devoid of or deficient in light or brightness; shadowed or black):

dark