rachis

R1A1C3H4I1S1
UK, US/ˈɹeɪkɪs/

noun

The spinal column, or the vertebrae of the spine.

Similar
spinal columnvertebral columnspinebackboneback
OriginNew Latin rhachis ← Ancient Greek ῥάχις →
UncommonFirst used 17th–19th c.Scrabble 11
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Meanings

nounrachis (plural rachises or rachides)

plural rachises · plural rachides · alternative rhachis

  1. obsoleteanatomyThe spinal column, or the vertebrae of the spine.First known use 17th–19th c.
  2. biologyAn anatomical shaft or axis in a marine invertebrate.First known use 18th c.

    In some squid species, the pen rachis flares out into wings on either side, and the tip of the rachis grows into a thick cone.

    2017, Danna Staaf, Squid Empire, ForeEdge, →ISBN, page 115
  3. biologyThe central shaft of a feather.First known use 19th c.
  4. biologyThe axis of either a compound leaf, inflorescence, or fern frond.First known use 19th c.

Synonyms & antonyms

nounthe series of vertebrae forming the axis of the skeleton and protecting the spinal cord

Similar
spinal columnvertebral columnspinebackboneback
Broader
skeletal structure
Also see
backbackbonemiddle ribmidribshaftspinal columnspinevertebral column

Synonym sets from Open English WordNet, CC BY 4.0.

Origin

  1. Ancient Greekῥάχις“spine, ridge”
  2. New Latinrhachis
  3. Englishrachis

From New Latin rhachis/rachis, from Ancient Greek ῥάχις (rhákhis, “spine, ridge”).

More words from New Latin, Ancient Greek

Full word history & related roots →

Translations

Bulgarian гръбнак, стъбло
  • гръбнак (grăbnak)spinal column — see also spinal column
  • стъбло (stăblo)central shaft of a feather
Catalan raquis, raquis
  • raquisspinal column — see also spinal column
  • raquiscentral shaft of a feather
  • raquismain shaft of a compound leaf or inflorescence
Esperanto rakio
  • rakiospinal column — see also spinal column
Finnish ruoti, ruoto
  • ruoticentral shaft of a feather
  • ruotocentral shaft of a feather
  • keskirankamain shaft of a compound leaf or inflorescence
  • lapakkomain shaft of a compound leaf or inflorescence
Polish stosina
  • stosinacentral shaft of a feather
Portuguese raque
  • raquecentral shaft of a feather
Romanian rahis, rahis
  • rahisspinal column — see also spinal column
  • rahiscentral shaft of a feather
  • rahismain shaft of a compound leaf or inflorescence
Spanish raquis, raquis
  • raquisspinal column — see also spinal column
  • raquiscentral shaft of a feather
  • raquismain shaft of a compound leaf or inflorescence

Rhymes & wordplay

Anagrams

CharisSirachRaisch
Cite this entry
APA

rachis. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/rachis

MLA

“rachis.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/rachis. Accessed November 2, 2026.

Chicago

WatkinsX Dictionary, s.v. “rachis,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/rachis.

Source: rachis on Wiktionary, CC BY-SA 4.0.