airhead vs slang

airhead and slang both are nouns.

Word	Noun	Adjective	Verb	Adverb
airhead	Yes	No	No	No
slang	Yes	No	Yes	No

airhead (noun)	slang (noun)
a bridgehead seized by airborne troops	a characteristic language of a particular group (as among thieves)
a flighty scatterbrained simpleton	informal language consisting of words and expressions that are not considered appropriate for formal occasions; often vituperative or vulgar