M., MONS., _Monsieur_ (Fr.). Mr or Sir;--MM., _Messieurs_, Gentlemen or
Sirs.
M.A. Master of Arts. See A.M.
M.A.B.Y.S. Metropolitan Association for Befriending Young Servants.
MAC., MACC. Maccabees.
MACH. Machinery.
MAD. Madam.
MAG. Magazine.
MAJ. Major.
MAL. Malachi.
MAR. March.
MARG. Margin, Marginal.
MARG., MRGT. Margaret.
MARQ. Marquis.
MAS., MASC. Masculine.
MASS. Massachusetts.
MATH. Mathematics.
MATT. Matthew.