The Element Encyclopedia of Witchcraft: The Complete A-Z for the Entire Magical World - Judika Illes 2005
Iynx is the name of a nymph, a bird, and an ancient Greek love charm. The famous charm consists of a miniature spinning wheel to which a wryneck bird is attached. It’s a very primitive device; it could be a child’s handmade toy, except for that poor suffering bird. The wheel is ritually spun, accompanied by incantations to draw and bind a lover. As the spellcaster murmurs and chants, she spins the toy, which makes a humming noise, similar to heavy breathing.
Iynx the nymph was a daughter of Pan and Echo. She invented the device that bears her name as an attempt to get back at Hera who had stolen Echo’s voice. Iynx used the device to force Zeus to fall for Io. Not to be outdone in this witch-war, the furious Hera promptly transformed Iynx into a wryneck.
What does the bird have to do with the charm? Why specifically a wryneck? The Greek word for the wryneck, a species of woodpecker, is iynx, named for its cry. (Allegedly the nymph announces her name so that family and friends will recognize her in her altered state.) The bird gets its English name, “wryneck,” from the characteristic movement of its head. When the wryneck is endangered or otherwise stressed, its defense mechanism is to extend its neck further than one would believe it could, twist it around and simultaneously fluff up its head feathers. With that long neck and puffed-up head, the wryneck resembles a snake—.causing its predators to think twice before attacking, and causing people to draw some other sexually-oriented comparisons.
Not surprisingly, the charm was a woman’s tool; its goal to make the man she desired behave like that wryneck—or at least the appropriate parts of him. (And if he wasn’t easily charmed, he’d be caught like that helpless bird. This isn’t a particularly nice spell—its intent is to assertively bind, rather than sweetly seduce.)
Perhaps wrynecks became scarce, perhaps the inherent cruelty became distasteful, or perhaps it was discovered that the spell worked better without the bird. Eventually the wryneck component was abandoned and the spell cast with only the wheel. Even so, it retained its name. Eventually the name came to refer to any sort of aggressive love spell, and then finally to any sort of malevolent spell, romantic or otherwise. That usage survives in English, albeit with the Latin spelling, “jinx.”