from The American Heritage® Dictionary of the English Language, 5th Edition.

  • abbreviation Grammar masculine
  • abbreviation Physics mass
  • abbreviation meter (measurement)
  • abbreviation mile
  • abbreviation minute
  • abbreviation Physics modulus
  • abbreviation Chemistry molality
  • noun The 13th letter of the modern English alphabet.
  • noun Any of the speech sounds represented by the letter m.
  • noun The 13th in a series.
  • noun Something shaped like the letter M.

from The Century Dictionary.

  • noun See A. M. .
  • noun An abbreviation of Member of Congress.
  • An abbreviation of Methodist Episcopal; of Mining Engineer: as, John Smith, M. E.; of Middle English: used (as Middle English) in the etymologies of this work.
  • An abbreviation of Major-General.
  • In musical notation, an abbreviation of the French main gauche (left hand), indicating that a note or passage is to be played with the left hand.
  • noun An abbreviation of Middle Latin or Medieval Latin.
  • noun An abbreviation of Maelzel's metronome. See metronome.
  • noun An abbreviation of Member of Parliament.
  • noun In music, an abbreviation of mano sinistra, ‘the left hand,’ noting a note or passage to be played with the left hand.
  • noun An abbreviation of the Latin Medicinæ Baccalaureus, Bachelor of Medicine;
  • noun of the Latin Musicæ Baccalaureus, Bachelor of Music;
  • noun of “mark of the beast,” in allusion to the popular belief that the garment described below smacked of popery.
  • noun An abbreviation of the Latin Medicinæ Doctor, Doctor of Medicine (see doctor, 2); in musical notation, of mano destra (Italian) or main droite (French), ‘right hand,’ indicating a passage to be performed by the right hand.
  • noun An abbreviation of the Latin Magister Chirurgiæ, Master of Surgery;
  • noun of Master of Ceremonies.
  • The thirteenth letter and tenth consonant in the English alphabet.
  • As a numeral, in the Roman system, M denotes 1,000. With a dash or stroke over it (M), it stands for a thousand times a thousand, or 1,000,000.
  • As a symbol
  • In the mnemonic words of logic (see mood), m indicates a transposition (metathesis) of the premises in the reduction.
  • Formerly, M was a brand impressed on one convicted of manslaughter and admitted to the benefit of clergy.
  • As an abbreviation
  • In titles, M. stands for Magister or Master, as in A. M.; for Medicinæ or Medicine, as in M. D.; or for Member, as in M. C, member of Congress, and M. P., member of Parliament.
  • In mech., m. stands for mass.
  • In dental formulæ, in zoöl., m. stands for molar, and dm. for deciduous molar.
  • In mathematics, M or μ stands for modulus; in higher geom., m or μ for the degree of a curve.
  • In astronomy and metrology, m. stands for minute (of time), and for meter; mm. for millimeter; and μ for micron or micromillimeter.
  • In musical notation, M. stands for mano (main), mezzo, metronome, and in organ-music for manual. See M. D., M. M., M. S.
  • In a ship's log-book, masculine is an abbreviation of mist.
  • In printing, the square or quadrate of any body of type: more commonly spelled out, em (which see).
  • noun An abbreviation of Middle Dutch;
  • noun of months (after) date.
  • noun Abbreviations of Mœsogothic.
  • noun An abbreviation
  • noun of Latin Musicæ Graduatus. Graduate of Music.
  • As a symbol:
  • M denotes magnetic moment: usually printed in old English; a gaseous pressure of the millionth of an atmosphere.
  • μ denotes magnetic permeability or the specific conductivity of any substance for lines of magnetic force; the coefficient of friction.
  • m stands for the intensity or strength of a magnetic pole.
  • m stands for square meters, m for cubic meters.


from Wiktionary, Creative Commons Attribution/Share-Alike License

Modification of capital letter M, from Ancient Greek letter Μ (M, "Mu").

from Wiktionary, Creative Commons Attribution/Share-Alike License

Various abbreviations

from Wiktionary, Creative Commons Attribution/Share-Alike License

From upper case roman numeral M (1000), an alteration of ⋈, from ∞, an alteration of ↀ, an alteration of Ⓧ, from encircling X (the roman numeral for ten) to indicate the hundredth ten.


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  • "I learned from Florey that the Egyptians used a wavelike symbol for water that the Phoenicians adapted and called mem—thus the letter M. I loved the soothing mindlessness of the exercises, particularly seeing the mmmm's break across the page—a tiny, rolling sea."

    —Emily Yoffe, "Dead Letters: Everyone Has Terrible Handwriting These Days,", seen here.

    September 12, 2009

  • Txt/twitterspeak for "am"

    September 30, 2015