mad apple

== English == === Alternative forms === mad-apple === Etymology === Calque of Renaissance Latin malum insanum, itself calqued from Italian melanzana, reanalyzed as if mela insana, perhaps under the influence of beliefs that it could cause various diseases. See further etymology at melongene. === Noun === mad apple (plural mad apples) (now rare) Eggplant. Thorn apple. Dead Sea apple. === References === “mad apple”, in Merriam-Webster.com Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.