rachis

or rha·chis

[ rey-kis ]
/ ˈreɪ kɪs /

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.

Origin of rachis

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

OTHER WORDS FROM rachis

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

British Dictionary definitions for rachidial

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

Medical definitions for rachidial (1 of 2)

rachidial
[ rā-kĭdē-əl, rə- ]

adj.

Relating to the vertebral column; spinal.

Medical definitions for rachidial (2 of 2)

rachis
[ rākĭs ]

n. pl. ra•chis•es

spinal column

Scientific definitions for rachidial

rachis
[ rākĭs ]

Plural rachises rachides (răkĭ-dēz′, rākĭ-)

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.