Webster's Revised Unabridged Dictionary · 1913

Sclerotium

Sclerotium , noun

[New Latin, from Greek sklhro`s hard.]

1.
(Botany) A hardened body formed by certain fungi, as by the Claviceps purpurea, which produces ergot.
2.
(Zoology) The mature or resting stage of a plasmodium.