rhachis

Webster's Dictionary (GCIDE)

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]

Rhachis \Rha"chis\, n.; pl. E. Rhachises, L. Rhachides. [See Rachis.] [Written also rechis.]

1.(Anat.) The spine. [1913 Webster]

2.(Bot.) (a) The continued stem or midrib of a pinnately compound leaf, as in a rose leaf or a fern. (b) The principal axis in a raceme, spike, panicle, or corymb. [1913 Webster]

3.(Zool.) (a) The shaft of a feather. The rhachis of the after-shaft, or plumule, is called the hyporhachis. (b) The central cord in the stem of a crinoid. (c) The median part of the radula of a mollusk. (d) A central cord of the ovary of nematodes. [1913 Webster]