M (ĕm). 1. M, the thirteenth
letter of the English alphabet, is a vocal consonant, and from the
manner of its formation, is called the labio-nasal consonant.
See Guide to Pronunciation, §§ 178-180,
242.
The letter M came into English from the Greek, through the
Latin, the form of the Greek letter being further derived from the
Phœnician, and ultimately, it is believed, from the Egyptian.
Etymologically M is related to n, in lime,
linden; emmet, ant; also to b.
M is readily followed by b and p. the position
of the lips in the formation of both letters being the same. The
relation of b and m is the same as that of d and
t to n. and that of g and k to
ng.
2. As a numeral, M stands for one thousand,
both in English and Latin.
M, n. 1.
(Print.) A quadrat, the face or top of which is a perfect
square; also, the size of such a square in any given size of type,
used as the unit of measurement for that type: 500 m's of pica would
be a piece of matter whose length and breadth in pica m's multiplied
together produce that number. [Written also em.]
2. (law) A brand or stigma, having the
shape of an M, formerly impressed on one convicted of manslaughter
and admitted to the benefit of clergy.
M roof (Arch.), a kind of roof formed
by the junction of two common roofs with a valley between them, so
that the section resembles the letter M.