extraneous vs immaterial

extraneous and immaterial both are adjectives.

Word	Noun	Adjective	Verb	Adverb
extraneous	No	Yes	No	No
immaterial	No	Yes	No	No

As adjectives, extraneous and immaterial are synonyms defined as:

extraneous and immaterial: not pertinent to the matter under consideration

Other synonyms of extraneous include impertinent, orthogonal.

extraneous (adjective)	immaterial (adjective)
not belonging to that in which it is contained; introduced from an outside source	not consisting of matter
not pertinent to the matter under consideration	of no importance or relevance especially to a law case
coming from the outside	without material form or substance
not essential	not pertinent to the matter under consideration
	(often followed by `to') lacking importance; not mattering one way or the other