What is the meaning of Ergot?

Any fungus in the genus Claviceps which are parasitic on grasses.

The sclerotium (wintering stage) of certain fungi in the genus Claviceps, appearing as a deformed grain in certain cereals and grasses infected by the fungi.

The wart-like growth of skin that covers the metacarpal pad on a horse or similar animal.

spur of a male member of Galliformes

ergot

ergot

Source: wiktionary.org