DICT.TW Dictionary Taiwan
Rha·chis n.; pl. E. Rhachises L. Rhachides [Written also rechis.]
1. Anat. The spine.
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.
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.
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