spiro

{ ‖‖ } 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 ]

n. [ L. spirare to breathe + -graph. ] (Physiol.) An instrument for recording the respiratory movements, as the sphygmograph does those of the pulse. [ 1913 Webster ]

n. [ L. spirare to breathe + -meter. ] An instrument for measuring the vital capacity of the lungs, or the volume of air which can be expelled from the chest after the deepest possible inspiration. Cf. Pneumatometer. [ 1913 Webster ]

n. The act or process of measuring the chest capacity by means of a spirometer. [ 1913 Webster ]

n. [ L. spirare to breathe + -scope. ] (Physiol.) A wet meter used to determine the breathing capacity of the lungs. [ 1913 Webster ]