clostridium \clostridium\ n. {clostridia}
1. spindle-shaped bacterial cell esp. one swollen at the
center by an endospore.
Syn: clostridia.
[WordNet 1.5]
2. [capitalized] a genus of anaerobic, spore-forming motile
bacteria of the family {Bacillaceae}, including several
pathogenic species, such as the causative agents of gas
gangrene ({Clostridium perfringens}), botulism
({Clostridium botulinum}), and tetanus ({Clostridium
tetani}).
[PJC]