My story today begins with the Greeks. Humans had been eating delicious delicious quince for thousands of years before that, since it was first domesticated in the area north and east of the Fertile Crescent; that is what is now Iran and the Caucasus. You can find people who will tell you it was the tempting fruit in the Garden of Eden, that it is referenced in the Song of Solomon and not the apple, and that its cultivation may have in fact preceded that of that apple. And yet apples get all the glory and I still have to describe it as a cross between a tennis ball and a pear.
It is the Greeks who came up with two of the more tenacious names for the fruit, both interestingly descriptive. First up is μελίμηλον (meli.melon, Latin melimelum)) "honey-apple." Melimelum is the runt of the litter here, with a limited distribution in extant languages. (Portuguese=marmelo, whence marmelade--originally a quince jelly.). Membrillo, the Spanish term for quince paste also comes to us from "melimelon," though Spanish does not continue this particular item itself for the name of the fruit or tree.
There was a certain kind of quince identified with a Minoan settlement on Crete in Κυδωνία (Kydonia, near present-day Khania), the κυδώνιον μήλον (kydonion melon) which gets into Latin as malum (Latin for apple) cotoneum/cydonium. This adjectival demonym deploys itself into a variety of forms in various languages.
It is therefore ultimately Kydonia we will be chasing through the dropping of Latin case endings, the devoicing or elision of that intervocal d, nasal palatalization, or the adoption of the term into a language with its own pholonological axes to grind.
Next time: More quince, of course, but also: why does "melon" mean apple? What does that have to do with cheese? What does any of that have to do with quinces? And why does "quinces" seem so awkward anyway?