1. [n]  concentration measured by the number of moles of solute per liter of solvent
2. [n]  the 13th letter of the Roman alphabet
3. [n]  the basic unit of length adopted under the System International d'Unites (approximately 1.094 yards)
4. [n]  the cardinal number that is the product of 10 and 100
5. [adj]  denoting a quantity consisting of 1,000 items or units

1. \M\ ([e^]m).
   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, [sect][sect] 178-180, 242.
   Note: The letter M came into English from the Greek, through
         the Latin, the form of the Greek letter being further
         derived from the Ph[oe]nician, 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.
   

2. \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.
   

1. Alternative name for MUMPS.

2. A C-like language from Silicon Compiler Systems for multilevel hardware description. It is currently available in the GDT package from Mentor Graphics.

[Jargon File]

3. The abbreviated for of mega-.