disaster vs disastrous

disaster is a noun but disastrous is not a noun.

Word	Noun	Adjective	Verb	Adverb
disaster	Yes	No	No	No
disastrous	No	Yes	No	No

disaster (noun)	disastrous (noun)
an act that has disastrous consequences
an event resulting in great loss and misfortune
a state of extreme (usually irremediable) ruin and misfortune

disaster (adjective)	disastrous (adjective)
	(of events) having extremely unfortunate or dire consequences; bringing ruin