M. D.—_Medicinæ Doctor_, Doctor of Medicine.

M. E.—Methodist Episcopal; Military or Mechanical Engineer;

Most excellent.

Me.—Maine.

Med.—Medicine.

Mem.—Memorandum.

Mem.—_Memento_, remember.

Merc.—Mercury.

Messrs. or MM.—Messieurs, Gentlemen.

Met.—Metaphysics.

Metal.—Metallurgy.

Meteor.—Meteorology.

Meth.—Methodist.

Mex.—Mexico or Mexican.

m. ft.—_Mistura fiat_, Let a mixture be made.

mg.—milligram, (metric system.)