desperate vs critical

desperate is a noun but critical is not a noun.

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

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

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