alveolar bed vs structure

alveolar bed and structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
alveolar bed	Yes	No	No	No
structure	Yes	No	Yes	No

As nouns, structure is a hypernym of alveolar bed; that is, structure is a word with a broader meaning than alveolar bed:

alveolar bed: lung tissue densely packed with alveoli
structure: a particular complex anatomical part of a living thing and its construction and arrangement

Other hypernyms of alveolar bed include anatomical structure, bodily structure, body structure, complex body part.

alveolar bed (noun)	structure (noun)
lung tissue densely packed with alveoli	a thing constructed; a complex entity constructed of many parts
	the manner of construction of something and the arrangement of its parts
	a particular complex anatomical part of a living thing and its construction and arrangement
	the complex composition of knowledge as elements and their combinations
	the people in a society considered as a system organized by a characteristic pattern of relationships

alveolar bed (verb)	structure (verb)
	give a structure to