- the axis of an inflorescence when somewhat elongated, as in a raceme.
- (in a pinnately compound leaf or frond) the prolongation of the petiole along which the leaflets are disposed.
- any of various axial structures.
- Ornithology. the part of the shaft of a feather bearing the web.
- Anatomy. spinal column.
Origin of rachis
1775–85; < New Latin < Greek rháchis spine, ridge, backbone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- 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
C17: via New Latin from Greek rhakhis ridge
- Relating to the vertebral column; spinal.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- 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.