"a gun which by means of a mechanism delivers a continuous fire of projectiles," 1870, from machine (n.) + gun (n.). As a verb, "to shoot down or kill by means of a machine gun," it is attested by 1915. Related: Machine-gunned; machine-gunning; machine-gunner.
A man is entitled to the fruits of his labor, and to assert a just claim is a duty as well as a right. In the year 1861 I first conceived the idea of a machine gun, which has been ever since the great controlling idea of my life; and it certainly cannot be regarded as egotism when I express the belief that I am the originator of the first successful weapon of the kind ever invented. [R.J. Gatling, quoted in Scientific American, Oct. 15, 1870]
Though in the light of subsequent advancements Gatling's invention of 1862 is not considered a modern machine-gun.
1680s; from machine (n.) + -ery. Originally theatrical, "devices for creating stage effects" (which also was a sense of Greek mēkhanē); meaning "machines or parts of machines considered collectively," is attested from 1731. Transferred meaning "any complex system of (non-mechanical) means to carry on a particular work" is by 1770. Middle English had machinament "a contrivance" (early 15c.).
1928 (n.) "tough guy," from Spanish macho "male animal," noun use of adjective meaning "masculine, virile," from Latin masculus (see masculine). As an adjective, "ostensibly manly and virile," attested in English by 1959 (Norman Mailer).
in Irish and pseudo-Irish expressions, by 1829, from Irish-Gaelic mo chroidhe "(of) my heart," hence "my dear!" The once-popular song "Mother Machree" ("I kiss the dear fingers so toil worn for me. Oh God bless you and keep you, Mother Machree") was written in 1910, popularized by John McCormack (1911) and other Irish tenors.
15c. Inca citadel high in the Andes Mountains of Peru, from Quechua (Inca) machu "old man" + pikchu "peak."
word-forming element meaning "battle, war, contest, fighting, warfare," from Latinized form of Greek -makhia, from makhē "a battle, fight," related to makhesthai "to fight." Beekes suspects it is from an isolated root, perhaps Pre-Greek: "In the domain of fighting and battle, old inherited expressions can hardly be expected."