rash vs heady

rash is a noun but heady is not a noun.

Word	Noun	Adjective	Verb	Adverb
rash	Yes	Yes	No	No
heady	No	Yes	No	No

As adjectives, rash and heady are synonyms defined as:

Other synonyms of rash include foolhardy, reckless.

rash (noun)	heady (noun)
a series of unexpected and unpleasant occurrences
any red eruption of the skin

rash (adjective)	heady (adjective)
marked by defiant disregard for danger or consequences	marked by defiant disregard for danger or consequences
imprudently incurring risk	extremely exciting as if by alcohol or a narcotic
	marked by the exercise of good judgment or common sense in practical matters