felt up vs mat up

felt up and mat up both are verbs.

Word	Noun	Adjective	Verb	Adverb
felt up	No	No	Yes	No
mat up	No	No	Yes	No

As verbs, felt up and mat up are synonyms defined as:

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

felt up (verb)	mat up (verb)
change texture so as to become matted and felt-like	change texture so as to become matted and felt-like