the.com/tinea

means A fungal skin infection that forms itchy, ring-shaped patches — despite the name, no worm is ever involved.

from From Latin 'tinea,' meaning 'gnawing worm' or 'moth larva' — the kind that eats through cloth and books. Ancient and medieval observers saw the spreading, ring-like patches on skin and assumed some small worm was burrowing and feeding beneath the surface, so they borrowed the word for the cloth-eating grub to name the condition. The worm theory was wrong — it's fungus all the way down — but the Latin name stuck, and 'tinea' remains the clinical term doctors use today.