improver

Meanings

1. Something that, or someone who, improves something.
2. Specifically, a person who improves land or property, a landscaper.
3. One who improves his or her performance, one who shows improvement (of individuals or groups).
4. A substance added to cause improvement (especially to a foodstuff).
5. A pad worn by women to make the dress hang properly.

1. One who performs improv; an improviser.

Etymology

From improve + -er.