felt vs matt-up

felt is a noun but matt-up is not a noun.

Word	Noun	Adjective	Verb	Adverb
felt	Yes	No	Yes	No
matt-up	No	No	Yes	No

As verbs, felt and matt-up are synonyms defined as:

Other synonyms of felt include felt up, mat, mat up, matte, matte up.

felt (noun)	matt-up (noun)
a fabric made of compressed matted animal fibers

felt (verb)	matt-up (verb)
change texture so as to become matted and felt-like	change texture so as to become matted and felt-like
cover with felt
mat together and make felt-like