Merriam-Webster Collegiate Dictionary - tetanus

 noun  Etymology: Middle English, from Latin, from Greek tetanos, from tetanos stretched, rigid; akin to Greek teinein to stretch — more at thin  Date: 14th century  1.  a. an acute infectious disease characterized by tonic spasm of voluntary muscles especially of the jaw and caused by the specific toxin of a bacterium (Clostridium tetani) which is usually introduced through a wound — compare lockjaw  b. the bacterium that causes ~  2. prolonged contraction of a muscle resulting from rapidly repeated motor impulses