1. 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
   "The grain inspector checked the rye for ergot contamination";
   - Claviceps purpurea
    
2. A plant disease caused by the ergot fungus
   "The rye field was contaminated with ergot, making the grain unsafe for consumption"

Derived forms: ergots

Type of: fungus, plant disease

Part of: Claviceps, genus Claviceps

Encyclopedia: Ergot