alteration

Noun

• the act of revising or altering (involving reconsideration and modification)
  • it would require a drastic revision of his opinion
    

• the act of making something different (as e.g. the size of a garment)

• an event that occurs when something passes from one state or phase to another
  • the change was intended to increase sales
    
  • this storm is certainly a change for the worse
    
  • the neighborhood had undergone few modifications since his last visit years ago
    

Related words

• Synonyms: 
  revision , modification , adjustment , change