rachis n 1: axis of a compound leaf or compound inflorescence 2: the series of vertebrae forming the axis of the skeleton and protecting the spinal cord; "the fall broke his back" [syn: {spinal column}, {vertebral column}, {spine}, {backbone}, {back}, {rachis}]
Rachis \Ra"chis\ (r[=a]"k[i^]s), n.; pl. E. {Rachises} (r[=a]"k[i^]s*[e^]z), L. {Rachides} (r[a^]k"[i^]*d[=e]z). [NL., fr. Gr. "ra`chis, -ios.] [Written also {rhachis}.] 1. (Anat.) The spine; the vertebral column. [1913 Webster] 2. (Bot. & Zool.) Same as {Rhachis}. [1913 Webster]