flooring vs truck bed

flooring and truck bed both are nouns.

Word	Noun	Adjective	Verb	Adverb
flooring	Yes	No	No	No
truck bed	Yes	No	No	No

As nouns, truck bed is a hyponym of flooring; that is, truck bed is a word with a more specific, narrower meaning than flooring:

flooring: the inside lower horizontal surface (as of a room, hallway, tent, or other structure)
truck bed: the floor or bottom of a wagon or truck or trailer

Other hyponyms of flooring include bell deck, dance floor, floorboard, parquet, parquet floor.

flooring (noun)	truck bed (noun)
the inside lower horizontal surface (as of a room, hallway, tent, or other structure)	the floor or bottom of a wagon or truck or trailer
building material used in laying floors