13th letter of the English alphabet, from Greek mu, from Semitic mem. It represents a very stable and unchanging sound in Indo-European, described by Johnson as "a kind of humming inward." The Roman symbol for 1,000; sometimes used in this sense in English 15c.-16c.; but in late 20c. newspaper headlines it stands for million. As a thickness of type, from 1680s (commonly spelled out, em).

childish or colloquial shortening of mamma, by 1823. "Also applied colloq. to a middle-aged or elderly woman, esp. one in authority" [OED].

also maam, 1660s, colloquial shortening of madam (q.v.). At one time the ordinary respectful form of address to a married woman; later restricted to the queen and royal princesses or used by servants to their mistresses. In U.S., used especially in answers, after yes or no.

Egyptian goddess, literally (in Egyptian) "truth."

early 15c., in Macabrees daunce, daunce of Machabree, a kind of morality show or allegorical representation of death and his victims, from Old French (danse) Macabré "(dance) of Death" (1376), which is of uncertain origin.

John Lydgate (c. 1370–c. 1451), the monk/poet who first translated it into English, seems to have regarded it as the name of the French author, and perhaps it was a French surname Macabré. Or perhaps it is from Medieval Latin (Chorea) Machabæorum, literally "dance of the Maccabees" (leaders of the Jewish revolt against Syro-Hellenes; see Maccabees). If so, the association with the dance of death (a favorite subject of literature and art in the Middle Ages) would be from vivid descriptions of the martyrdom of the Maccabees in the Apocryphal books.

The typical form which the allegory takes is that of a series of pictures, sculptured or painted, in which Death appears, either as a dancing skeleton or as a shrunken corpse wrapped in grave-clothes to persons representing every age and condition of life, and leads them all in a dance to the grave. [ Encyclopaedia Britannica, 11th ed., 1911]

 The abstracted sense of "characterized by gruesomeness" is attested 1842 in French, by 1889 in English. Related: Macaberesque.

"material of which macadamized pavement is made," 1826, earlier as an adjective (1824), named for its inventor, Scottish civil engineer John L. McAdam (1756-1836), who developed a method of leveling roads and paving them with gravel and outlined the process in his pamphlet "Remarks on the Present System of Road-Making" (1822). Originally the word meant road material consisting of a solid mass of stones of nearly uniform size laid down in layers (McAdam did not approve of the use of binding materials or rollers). The idea of mixing tar with the gravel began 1880s.

"process of laying roads according to the system of John L. McAdam;" 1824, noun of action from macadamize (see macadam).

"to cover (a road) with gravel and broken stone according to the system of John L. McAdam," 1824 (implied in macadamizer), from macadam + -ize. In early use also mcadamize. Related: Macadamized; macadamizing. Also macadamise, macadamised.

Australian evergreen tree, commercially important for its edible nut, 1904, from Modern Latin (1858), named for Scotland-born chemist Dr. John Macadam, secretary of the Victoria Philosophical Institute, Australia, + abstract noun ending -ia.

East Indian monkey, 1757, from French macaque, from Portuguese macaco "monkey," a Bantu word brought from Africa to Brazil (where it was applied 17c. to a type of monkey there). Introduced as a genus name 1840.