critical vs desperate

critical is not a noun while desperate is a noun.

Word	Noun	Adjective	Verb	Adverb
critical	No	Yes	No	No
desperate	Yes	Yes	No	No

critical (noun)	desperate (noun)
	a person who is frightened and in need of help

critical (adjective)	desperate (adjective)
marked by a tendency to find and call attention to errors and flaws	showing extreme courage; especially of actions courageously undertaken in desperation as a last resort
characterized by careful evaluation and judgment	fraught with extreme danger; nearly hopeless
being in or verging on a state of crisis or emergency	arising from or marked by despair or loss of hope
at or of a point at which a property or phenomenon suffers an abrupt change especially having enough mass to sustain a chain reaction	showing extreme urgency or intensity especially because of great need or desire
of or involving or characteristic of critics or criticism	desperately determined
forming or having the nature of a turning point or crisis	(of persons) dangerously reckless or violent as from urgency or despair
urgently needed; absolutely necessary