success vs unsuccessful

success is a noun but unsuccessful is not a noun.

Word	Noun	Adjective	Verb	Adverb
success	Yes	No	No	No
unsuccessful	No	Yes	No	No

success (noun)	unsuccessful (noun)
an attainment that is successful
an event that accomplishes its intended purpose
a person with a record of successes
a state of prosperity or fame

success (adjective)	unsuccessful (adjective)
	not successful; having failed or having an unfavorable outcome
	failing to accomplish an intended result