2. Music. major.
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.
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.
4. Biochem. methionine.