alter is on the Academic Word List.

Pronunciation

change

Plain form
alter

Third-person singular
alters

Past tense
altered

Past participle
altered

Present participle
altering

  1. (transitive & intransitive) If you alter something, you change it, usually in a small way.
    The design can be easily altered by selecting new colours, materials, etc.
    But not even a good cleaning would alter the fact that the room was dark and unfriendly.
    Because he was so short, he always needed to have his pants altered to fit him.
change