Possessing an extraordinarily large penis. (adjective)(also Mentulated)
More common in old 'bodice-ripper' novels; a term for "well hung" that lends a certain appearance of culture to your p0rn.
My brother said I'm mental. I proclaimed I'm not mental, he then stated that I'm retarded no I'm not retarted he then claimed that im Mentarted and that's where it all started.