cadmium
toxic zinc-borne metal
Today this word meansA heavy metal that occurs with zinc — the cause of itai-itai disease.
From Latin cadmia, a word for zinc ore, which in turn connects to the name of Cadmus, founder of Thebes.
Tradition has it the name arose because that ore was found near the Thebes Cadmus built.
Worth noting
The path is indirect: myth → place-name → ore → element. Saying flatly "cadmium comes from myth" skips a step too far.