What's the "een" in Halloween?
edible fish, c.1300, from Old French maquerel "mackerel" (Modern French maquereau), of unknown origin but apparently identical with Old French maquerel "pimp, procurer, broker, agent, intermediary," a word from a Germanic source (cf. Middle Dutch makelaer "broker," from Old Frisian mek "marriage," from maken "to make"). The connection is 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.
any of a number of swift-moving, streamlined food and sport fishes found in temperate and tropical seas around the world, allied to tunas in the family Scombridae (order Perciformes). Mackerels are rounded and torpedo-shaped, with a slender, keeled tail base, a forked tail, and a row of small finlets behind the dorsal and anal fins. They are carnivorous fishes and feed on plankton, crustaceans, mollusks, fish eggs, and small fish. They congregate in schools and swim actively in the upper 25-30 fathoms of the water in the warmer months and then descend to as deep as 100 fathoms during the winter. They spawn during the spring and early summer along coastlines. Their eggs average 1 mm (0.04 inch) in diameter, are buoyant, and drift in the uppermost five fathoms of water. Mackerels are mostly caught by nets, rather than by angling.