The New Student's Reference Work/M

M (ěm), the thirteenth letter, is a vocal consonant. It is made with the lips and nasal passages closed, and is therefore classed as a labionasal, as in me,him, tame. It also is a liquid and even a semivowel. Before n in the same syllable it is silent, as in mnemonics. The Romans used it as a numeral (1,000) as well as a letter. M also means em, a printer's term.