weldment vs assembly

weldment and assembly both are nouns.

Word	Noun	Adjective	Verb	Adverb
weldment	Yes	No	No	No
assembly	Yes	No	No	No

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

weldment: an assembly of parts welded together
assembly: a group of machine parts that fit together to form a self-contained unit

weldment (noun)	assembly (noun)
an assembly of parts welded together	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