rhachis

rhachis is a   Noun

Definition:

[1] The spine.

[2] The continued stem or midrib of a pinnately compound leaf, as in a rose leaf or a fern.

[3] The principal axis in a raceme, spike, panicle, or corymb.

[4] The shaft of a feather. The rhachis of the after-shaft, or plumule, is called the hyporhachis.

[5] The central cord in the stem of a crinoid.

[6] The median part of the radula of a mollusk.

[7] A central cord of the ovary of nematodes.

Synonyms: