void vs thin air

void and thin air both are nouns.

Word	Noun	Adjective	Verb	Adverb
void	Yes	Yes	Yes	No
thin air	Yes	No	No	No

As nouns, thin air is a hyponym of void; that is, thin air is a word with a more specific, narrower meaning than void:

void (noun)	thin air (noun)
an empty area or space	nowhere to be found in a giant void
the state of nonexistence

void (adjective)	thin air (adjective)
containing nothing
lacking any legal or binding force

void (verb)	thin air (verb)
excrete or discharge from the body
take away the legal force of or render ineffective
clear (a room, house, place) of occupants or empty or clear (a place or receptacle) of something
declare invalid