{ ‖‖ } n. [ L. spira a coil + Gr. &unr_;&unr_;&unr_; hair. ] (Biol.) A genus of Spirobacteria similar to Spirillum, but distinguished by its motility. One species, the Spirochaete Obermeyeri, is supposed to be the cause of relapsing fever. [ 1913 Webster ]