A person who is highly skilled at the art of cunnilingus.
Andrea gets pissed off with her boyfriend all the time but never breaks up with him. He must be a muffmaster!
by Chad Apollo September 29, 2017
A very smart, or intelligent person, much more than people normally are, yet are at particular times they become very inept or foolish at other everyday things.
Kim is such a muff master, she is very intelligent, yet at times makes really silly mistakes.
by Byrappa September 25, 2013