extemporaneous vs unrehearsed

extemporaneous and unrehearsed both are adjectives.

Word	Noun	Adjective	Verb	Adverb
extemporaneous	No	Yes	No	No
unrehearsed	No	Yes	No	No

As adjectives, extemporaneous and unrehearsed are synonyms defined as:

extemporaneous and unrehearsed: with little or no preparation or forethought

Other synonyms of extemporaneous include ad-lib, extemporary, extempore, impromptu, off-the-cuff, offhand, offhanded.

extemporaneous (adjective)	unrehearsed (adjective)
with little or no preparation or forethought	with little or no preparation or forethought