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.

Milk and water.  Both ends of the busk.

To milk the pigeon.  To endeavour at impossibilities.

Milling cove.  A boxer.  How the milling cove served
  the cull out; how the boxer beat the fellow.

Mill.  A chisel.

To mill.  To rob; also to break, beat out, or kill.  I’ll
  mill your glaze; I’ll beat out your eye.  To mill a bleating
  cheat; to kill a sheep.  To mill a ken; to rob a house. 
  To mill doll; to beat hemp in bridewell.  Cant.

Mill lay.  To force open the doors of houses in order to
  rob them.

Miller.  A murderer.

Mine A-se on A bandbox.  An answer to the offer of any
  thing inadequate to the purpose for which it is wanted, just
  as a bandbox would be if used for a seat.

Mine uncle’s.  A pawnbroker’s shop; also a necessary
  house.  Carried to my uncle’s; pawned.  New-married
  men are also said to go to their uncle’s, when they leave
  their wives soon after the honey moon.

Minikin.  A little man or woman:  also the smallest sort
  of pin.

Minor clergy.  Young chimney sweepers.

Mint.  Gold.  A mint of money; common phrase for a
  large sum.

Mischief.  A man loaded with mischief, i.e. a man with
  his wife on his back.

Mish.  A shirt, smock, or sheet.  Cant.

Mish Topper.  A coat, or petticoat.

Miss.  A miss or kept mistress; a harlot.

Miss Laycock.  The monosyllable.

Mite.  A nick name for a cheesemonger:  from the small
  insect of that name found in cheese.

MIX metal.  A silversmith.

MOABITES.  Bailiffs, or Philistines.

Mob; or Mab.  A wench, or harlot.

Mobility.  The mob:  a sort of opposite to nobility.