A poet who composes or performs verse extemporaneously.
Originally and chiefly with reference to the Italian tradition of improvisational poetry which was at its height in the late 17th to mid 19th centuries..
Origin
Mid 18th century; earliest use found in Tobias Smollett (1721–1771), writer. From Italian improvvisatore, †improvisatore poet who composes or performs verse extemporaneously from improvvisare + -atore.