Definitions for toadstoneˈtoʊdˌstoʊn
Random House Webster's College Dictionary
any of various stonelike objects, usu. fossilized animal parts, formerly supposed to have been formed in the body of a toad, worn esp. as amulets to protect against poison.
A small stone, once believed to be a jewel embedded in the head of a toad, worn as a amulet
a local name for the igneous rocks of Derbyshire, England; -- said by some to be derived from the German todter stein, meaning dead stone, that is, stone which contains no ores
bufonite, formerly regarded as a precious stone, and worn as a jewel. See Bufonite