sober in WordNet English dictionary

1. lacking brightness or color; dull
   "drab faded curtains"; "sober Puritan grey"; "children in somber brown clothes"
   drab  sober  somber  sombre 
   
2. dignified and somber in manner or character and committed to keeping promises
   "a grave God-fearing man"; "a quiet sedate nature"; "as sober as a judge"; "a solemn promise"; "the judge was solemn as he pronounced sentence"
   grave  sedate  sober  solemn 
   
3. completely lacking in playfulness
   unplayful  serious  sober 
   
4. not affected by a chemical substance (especially alcohol)
   sober 
   

1. become sober after excessive alcohol consumption
   "Keep him in bed until he sobers up"
   sober up  sober 
   
2. become more realistic
   "After thinking about the potential consequences of his plan, he sobered up"
   sober up  sober 
   
3. cause to become sober
   "A sobering thought"
   sober