—adj. 1. not intoxicated or drunk.
2. habitually temperate, esp. in the use of liquor.
3. quiet or sedate in demeanor, as persons.
4. marked by seriousness, gravity, solemnity, etc., as of demeanor, speech, etc.: a sober occasion. 5. subdued in tone, as color; not gay or showy, as clothes.
6. free from excess, extravagance, or exaggeration: sober facts. 7. showing self-control: sober restraint. 8. sane or rational: a sober solution to the problem.
—v.t., v.i. to make or become sober: (often fol. by up).