Pronunciation: (em),[key] —n., —pl.M's or Ms, m's or ms. 1. the thirteenth letter of the English alphabet, a consonant.
2. any spoken sound represented by the letter M or m, as in my, summer, or him. 3. something having the shape of an M. 4. a written or printed representation of the letter M or m. 5. a device, as a printer's type, for reproducing the letter M or m. 6. Print.em.
9. modal auxiliary.
11. Econ.monetary aggregate: issued periodically by the Federal Reserve Board as various measures of money supply ( M-1, M-1A, M-2, etc.). Cf. L. 12. Brit.motorway (used with a road number to designate a major highway): the M1.
—Symbol. 1. the thirteenth in order or in a series, or, when I is omitted, the twelfth.
2. (sometimes l.c.) the Roman numeral for 1000. Cf. Roman numerals. 3. Elect.magnetization.