ergot

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A fungus (Claviceps purpurea) that infects various cereal plants and forms compact black masses of branching filaments that replace many of the grains of the host plant.
2. n. The disease caused by such a fungus.
3. n. The dried sclerotia of ergot, usually obtained from rye seed and used as a source of several medicinally important alkaloids and as the basic source of lysergic acid.

Century Dictionary and Cyclopedia

1. n. In farriery, a stub, like a piece of soft horn, of about the size of a chestnut, situated behind and below the pastern-joint, and commonly hidden under the tuft of the fetlock.
2. n. A morbid growth arising from a diseased condition of the ovary of various grasses, caused by a fungus of the genus Claviceps. The growth of the fungus begins by the formation of a filamentous mycelium upon the surface of the ovary, which it destroys and displaces, retaining approximately its shape. The surface of this tissue is marked by furrows. At this stage conidia are produced upon the tips of short hyphæ; and in this form it was formerly considered a distinct species, under the generic name Sphacelia (which has become a common name coordinate with sclerotium). When the formation of conidia is at its height, a thick belt of more compact hyphæ is formed at the base of the mass. This assumes a dark-violet color, and continues to grow, pushing upward the sphacelia, which is torn from its attachments, and soon falls off. The resulting structure is the sclerotium or ergot. It is a horn-like mass, often one inch in length. It lies dormant till fall or usually till the following spring, when branches arise in a tuft. Each becomes a stroma, consisting of a stalk and a small head. In the head are formed a number of fiask-shaped perithecia, each containing many asci, of which each in turn incloses several filiform spores. The ergot of rye is caused by Claviceps purpurea. Ergot is said to cause a sort of gangrene in cattle, especially in the feet. It is used in medicine to cause contraction of the uterus and of the arterioles and as an abortifacient, and also in certain morbid states of the cerebrospinal axis, where its effect may or may not be due entirely to its action on the vessels. Also called spurred rye.
3. n. In anatomy, the calcar. spur, or hippocampus minor of the brain.
4. To infer; arrive at.
5. To draw conclusions.

Wiktionary

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

GNU Webster's 1913

1. n. A diseased condition of rye and other cereals, in which the grains become black, and often spur-shaped. It is caused by a parasitic fungus, Claviceps purpurea.
2. n. The mycelium or spawn of this fungus infecting grains of rye and wheat. It is a powerful remedial agent, and also a dangerous poison, and is used as a means of hastening childbirth, and to arrest bleeding.
3. n. (Far.) A stub, like soft horn, about the size of a chestnut, situated behind and below the pastern joint.
4. n. (Anat.) See 2d Calcar, 3 (b).

WordNet 3.0

1. n. a fungus that infects various cereal plants forming compact black masses of branching filaments that replace many grains of the plant; source of medicinally important alkaloids and of lysergic acid
2. n. a plant disease caused by the ergot fungus