Impossible to prove.

Third-person singular simple present indicative form of improve

simple past tense and past participle of improvize

Something that, or someone who, improves something. / (obsolete) Specifically, a person who improves land or property, a landscaper.

plural of improver

The condition of being improvable

plural of improv

Third-person singular simple present indicative form of improv

Third-person singular simple present indicative form of improvize

present participle of improvize