legislative body vs assembly

legislative body and assembly both are nouns.

Word	Noun	Adjective	Verb	Adverb
legislative body	Yes	No	No	No
assembly	Yes	No	No	No

As nouns, assembly is a hypernym of legislative body; that is, assembly is a word with a broader meaning than legislative body:

legislative body (noun)	assembly (noun)
persons who make or amend or repeal laws	the social act of assembling
	the act of constructing something (as a piece of machinery)
	a group of machine parts that fit together to form a self-contained unit
	a public facility to meet for open discussion
	a unit consisting of components that have been fitted together
	a group of persons who are gathered together for a common purpose