belittle in WordNet English dictionary

1. lessen the authority, dignity, or reputation of
   "don't belittle your colleagues"
   diminish  belittle 
   
2. express a negative opinion of
   "She disparaged her student's efforts"
   disparage  belittle  pick at 
   
3. cause to seem less serious; play down
   "Don't belittle his influence"
   minimize  belittle  denigrate  derogate