alteration

(noun) an event that occurs when something passes from one state or phase to another. Synonyms: change, modification. Examples: "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."

(noun) the act of making something different (as e.g. the size of a garment). Synonyms: modification, adjustment.

(noun) the act of revising or altering (involving reconsideration and modification). Synonyms: revision. Example: "It would require a drastic revision of his opinion."