alteration
noun [ C or U ]
uk/ˌɔːltərˈeɪʃən/ usa change in the appearance, character, or structure of something:
an alteration to sth Some alterations to our original plans might be necessary.
If you have made any alterations since you last saved the document, a warning message will appear.
significant/major alteration The report's recommendations should be adopted without major alteration.