"male virility, masculine pride," 1940, from American Spanish machismo, from Spanish macho "male" (see macho) + ismo (see -ism).

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."

proprietary name for a brand of heavy automobile trucks, named for brothers John M., Augustus F., and William C. Mack, who established Mack Brothers Company, N.Y., N.Y., in 1902. Their trucks have been formally known as Mack Trucks from 1910.

river in Canada, named for Scottish fur trader and explorer Sir Alexander Mackenzie, who discovered and explored it 1789.

edible fish of the North Atlantic (Scomber scombrus), c. 1300, from Old French maquerel "mackerel" (Modern French maquereau), of unknown origin; perhaps so called from the dark blotches with which the fish is marked, from Latin macula "spot, stain" (see macula). But the word is apparently identical with Old French maquerel "pimp, procurer, broker, agent, intermediary" (itself attested in English in this sense by early 15c.), a word from a Germanic source (compare Middle Dutch makelaer "broker," from Old Frisian mek "marriage," from maken "to make").

The connection would be obscure, but medieval people had imaginative notions about the erotic habits of beasts. The fish approach the shore in shoals in summertime to spawn. Exclamation holy mackerel is attested from 1876.

port and island in Michigan in the straits connecting lakes Michigan and Huron, from Mackinac, from Ojibway (Algonquian) mitchimakinak "many turtles," from mishiin- "be many" + mikinaak "snapping turtle."

As a type of flat-bottomed, flat-sided boat with a sharp prow and a square stern, 1812, so called because used on the Great Lakes. As a type of heavy blanket given to the Indians by the U.S. government, it is attested from 1822, so called because the fort there was for many years the most remote U.S. spot in the Northwest and many Native Americans received their supplies there..

waterproof outer coat or cloak, 1836, named for Charles Macintosh (1766-1843), inventor of a waterproofing process (patent #4804, June 17, 1823). The surname is from Gaelic Mac an toisich "Son of the chieftain."

also mackle, "a spot, a blemish," 1706, from French macle "a spot," from Latin macula (see macula). Also as a verb (1590s). Related: Macled; mackled; mackling.