convention vs unconventional

convention is a noun but unconventional is not a noun.

Word	Noun	Adjective	Verb	Adverb
convention	Yes	No	No	No
unconventional	No	Yes	No	No

convention (noun)	unconventional (noun)
the act of convening
orthodoxy as a consequence of being conventional
something regarded as a normative example
(diplomacy) an international agreement
a large formal assembly

convention (adjective)	unconventional (adjective)
	not conforming to accepted rules or standards
	not conventional or conformist
	not conforming to legality, moral law, or social convention