I. noun — [ mass noun] 1. the action or process of altering or being altered • careful alteration of old buildings
• [ count noun]
alterations had to be made.
II. derivatives alterative /ˈɔːltərətɪv, ˈɒltərətɪv / adjective
– origin late Middle English: from Old French, or from late Latin alteratio(n-), from the verb alterare (see alter).