bridgehead vs airhead

bridgehead and airhead both are nouns.

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

As nouns, airhead is a hyponym of bridgehead; that is, airhead is a word with a more specific, narrower meaning than bridgehead:

bridgehead: an area in hostile territory that has been captured and is held awaiting further troops and supplies
airhead: a bridgehead seized by airborne troops

Other hyponyms of bridgehead include beachhead.

bridgehead (noun)	airhead (noun)
an area in hostile territory that has been captured and is held awaiting further troops and supplies	a bridgehead seized by airborne troops
a defensive post at the end of a bridge nearest to the enemy	a flighty scatterbrained simpleton