1. An acute, often fatal disease characterized by spasmodic contraction of voluntary muscles, especially those of the neck and jaw, and caused by the toxin of the bacterium Clostridium tetani, which typically infects the body through a deep wound. Also called lockjaw.
2. Physiology A state of continuous muscular contraction, especially when induced artificially by rapidly repeated stimuli.
[Middle English, from Latin, from Greek tetanos, rigid, tetanus; see ten- in the Appendix of Indo-European roots.]
teta·nal (tĕtn-əl) adj.
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