understructure vs structure

understructure and structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
understructure	Yes	No	No	No
structure	Yes	No	Yes	No

understructure (noun)	structure (noun)
lowest support of a structure	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

understructure (verb)	structure (verb)
	give a structure to