undermentioned vs following

undermentioned is not a noun while following is a noun.

Word	Noun	Adjective	Verb	Adverb
undermentioned	No	Yes	No	No
following	Yes	Yes	No	No

As adjectives, undermentioned and following are synonyms defined as:

undermentioned (noun)	following (noun)
	the act of pursuing in an effort to overtake or capture
	a group of followers or enthusiasts

undermentioned (adjective)	following (adjective)
about to be mentioned or specified	going or proceeding or coming after in the same direction
	in the desired direction
	about to be mentioned or specified
	immediately following in time or order