Source : Webster's Revised Unabridged Dictionary (1913)

Spirochaeta \Spi`ro*ch[ae]"ta\, Spirochaete \Spi`ro*ch[ae]"te\,
   n. [L. spira a coil + Gr. ??? hair.] (Biol.)
   A genus of Spirobacteria similar to Spirillum, but
   distinguished by its motility. One species, the
   {Spiroch[ae]te Obermeyeri}, is supposed to be the cause of
   relapsing fever.