severe

adj. 1 rigorous and harsh (severe critic). 2 serious (severe shortage). 3 forceful (severe storm). 4 extreme (severe winter). 5 exacting (severe competition). 6 plain in style.  severely adv. Severity n. [latin severus]

superl. Serious in feeeling or manner; sedate; grave; austere; not light, lively, or cheerful.