• WordNet 3.6
    • n rachis the series of vertebrae forming the axis of the skeleton and protecting the spinal cord "the fall broke his back"
    • n rachis axis of a compound leaf or compound inflorescence
    • ***
Webster's Revised Unabridged Dictionary
    • Rachis (Bot. & Zoöl) Same as Rhachis.
    • Rachis (Anat) The spine; the vertebral column.
    • ***
Century Dictionary and Cyclopedia
    • n rachis In botany:
    • n rachis The axis of an inflorescence when somewhat elongated; the continuation of the peduncle along which the flowers are ranged, as in a spike or a raceme.
    • n rachis In a pinnately compound leaf or frond, the prolongation of the petiole along which the leaflets or pinnæ are disposed, corresponding to the midrib of a pinnately veined simple leaf. See cut under compound.
    • n rachis In zoöl. and anatomy:
    • n rachis The vertebral column.
    • n rachis The stem, shaft, or scape of a feather, as distinguished from the web, vane, or vexillum; especially, that part of the stem which bears the vexillum. as distinguished from the calamus or quill. See quill, 4.
    • n rachis The median part of the radula of a mollusk, usually bearing teeth which differ from those on each side of it.
    • n rachis The axial skeleton of various polyp-colonies, as of Gorgonia; some axial part, or formation like a midrib, as in crinoids.
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Chambers's Twentieth Century Dictionary
    • n Rachis rā′kis the spine:
    • n Rachis rā′kis (bot.) a branch or axis of inflorescence which proceeds in nearly a straight line from the base to the apex
    • ***


Webster's Revised Unabridged Dictionary
NL., fr. Gr. "ra`chis -ios
Chambers's Twentieth Century Dictionary
Gr. rachis, the spine.


In literature:

Meanwhile the Pope has persuaded the Lombard king Rachis to go into a monastery.
"The Roman and the Teuton A Series of Lectures delivered before the University of Cambridge" by Charles Kingsley
CASSIA (zygophylla), glabra foliis unijugis; foliolis linearibus planis rachi duplo latioribus, corymbis paucifloris folio brevioribus.
"Expedition into Central Australia" by Charles Sturt
Sterile pinnae palmate; rachis twining.
"The Fern Lover's Companion" by George Henry Tilton
The ovicells arise from the back of the rachis towards the side.
"Narrative Of The Voyage Of H.M.S. Rattlesnake, Commanded By The Late Captain Owen Stanley, R.N., F.R.S. Etc. During The Years 1846-1850. Including Discoveries And Surveys In New Guinea, The Louisiade Archipelago, Etc. To Which Is Added The Account Of Mr. E.B. Kennedy's Expedition For The Exploration Of The Cape York Peninsula. By John Macgillivray, F.R.G.S. Naturalist To The Expedition. In Two Volumes. Volume 1." by John MacGillivray
The name =rachis= is given to the axis of the spike, raceme and panicle, whether the axis is the main one or of the branch.
"A Handbook of Some South Indian Grasses" by Rai Bahadur K. Ranga Achariyar
Section of the rachis bearing a single pinna, a, Axis; b, metarachidial; c, prorachidial; d, pararachidial stem canals.
"Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 2" by Various
The father of the Lombard king Rachis was called Pimo.
"Surnames as a Science" by Robert Ferguson
A. Spikelets one-flowered, rarely two-flowered as in Zea, falling from the pedicel entire or with certain joints of the rachis at maturity.
"Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 3" by Various
The grass head was slowly rotated and shifted sideways until nothing remained but the rachis which was discarded.
"North American Jumping Mice (Genus Zapus)" by Philip H. Krutzsch
His successors, Rachis and Aistolf, attempted to follow the same game of conquest.
"Encyclopaedia Britannica, 11th Edition, Volume 15, Slice 1" by Various