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rachis

or rha·chis

[ rey-kis ]
/ ˈreɪ kɪs /
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noun, plural ra·chis·es, rach·i·des [rak-i-deez, rey-ki-]. /ˈræk ɪˌdiz, ˈreɪ kɪ-/.
Botany.
  1. the axis of an inflorescence when somewhat elongated, as in a raceme.
  2. (in a pinnately compound leaf or frond) the prolongation of the petiole along which the leaflets are disposed.
  3. any of various axial structures.
Ornithology. the part of the shaft of a feather bearing the web.
Anatomy. spinal column.
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Origin of rachis

1775–85; <New Latin <Greek rháchis spine, ridge, backbone

OTHER WORDS FROM rachis

ra·chid·i·an [ruh-kid-ee-uhn], /rəˈkɪd i ən/, ra·chi·al [rey-kee-uhl], /ˈreɪ ki əl/, ra·chid·i·al, adjective

Words nearby rachis

race walking, raceway, Rachel, rachilla, rachiotomy, rachis, rachitis, Rachmaninoff, Rachmanism, racial, racialism
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Words related to rachis

bone, vertebrae, axis, axle, baluster, mandrel, pin, rod, shaft, stalk, stem, back, chine, ridge, backbone, myel, rhachis, spine, spinal column, vertebral column

How to use rachis in a sentence

British Dictionary definitions for rachis

rachis

rhachis

/ (ˈreɪkɪs) /
noun plural rachises, rhachises, rachides or rhachides (ˈrækɪˌdiːz, ˈreɪ-)
botany the main axis or stem of an inflorescence or compound leaf
ornithol the shaft of a feather, esp the part that carries the barbs
another name for spinal column

Derived forms of rachis

rachial or rhachial (ˈreɪkɪəl) or rachidial or rhachidial (rəˈkɪdɪəl), adjective

Word Origin for rachis

C17: via New Latin from Greek rhakhis ridge
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for rachis

rachis
[ rā′kĭs ]
Plural rachises rachides (răk′ĭ-dēz′, rā′kĭ-)
A main axis or shaft, such as the main stem of an inflorescence, the stalk of a pinnately compound leaf, the shaft of a feather, or the spinal column.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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