unpremeditated vs unplanned

unpremeditated and unplanned both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unpremeditated	No	Yes	No	No
unplanned	No	Yes	No	No

unpremeditated (adjective)	unplanned (adjective)
not premeditated	without apparent forethought or prompting or planning
not prepared or planned in advance	not done with purpose or intent