diminish

Verb

• lessen the authority, dignity, or reputation of
  • don't belittle your colleagues
    

• decrease in size, extent, or range
  • The amount of homework decreased towards the end of the semester
    
  • The cabin pressure fell dramatically
    
  • her weight fell to under a hundred pounds
    
  • his voice fell to a whisper
    

Related words

• Synonyms: 
  belittle , decrease , lessen , fall