largely vs for the most part

largely and for the most part both are adverbs.

Word	Noun	Adjective	Verb	Adverb
largely	No	No	No	Yes
for the most part	No	No	No	Yes

As adverbs, largely and for the most part are synonyms defined as:

Other synonyms of largely include mostly.

largely (adverb)	for the most part (adverb)
in large part; mainly or chiefly	in large part; mainly or chiefly
on a large scale