component vs residuum

component and residuum both are nouns.

Word	Noun	Adjective	Verb	Adverb
component	Yes	No	No	No
residuum	Yes	No	No	No

As nouns, residuum is a hyponym of component; that is, residuum is a word with a more specific, narrower meaning than component:

component (noun)	residuum (noun)
an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system	something left after other parts have been taken away
an abstract part of something
something determined in relation to something that includes it