MERRY A-SE CHRISTIAN. A whore.
MERRY-BEGOTTEN. A bastard.
MAN OF THE WORLD. A knowing man.
MESS JOHN. A Scotch presbyterian teacher or parson.
MESSMATE. One who eats at the same mess, companion or
comrade.
METTLE. The semen. To fetch mettle; the act of self pollution.
Mettle is also figuratively used for courage.
METTLESOME. Bold, courageous.
MICHAEL. Hip, Michael, your head's on fire. See HYP.
MIDSHIPMAN'S WATCH AND CHAIN. A sheep's heart and pluck.
MILCH COW. One who is easily tricked out of his property; a term used by gaolers, for prisoners who have money and bleed freely.