rachis

See also: Rachiș

English

Alternative forms

• rhachis

Etymology

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

Pronunciation

• (UK, US) IPA^(key): /ˈɹeɪkɪs/

Noun

rachis (plural rachises or rachides)

1. (obsolete, zoology, anatomy) The spinal column, or the vertebrae of the spine. [17th–19th c.]
2. (zoology) An anatomical shaft or axis in a marine invertebrate. [from 18th c.]
   • 2017, Danna Staaf, Squid Empire, ForeEdge, →ISBN, page 115:

     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.

3. (ornithology) The central shaft of a feather. [from 19th c.]
4. (botany) The main shaft of either a compound leaf, head of grain, or fern frond. [from 19th c.]

Usage notes

• The plural form rachides is based on a mistaken impression of the Ancient Greek stem.

Derived terms

• rhachidian, rachidian

Translations

spinal column — see also spinal column

• Bulgarian: гръбнак m (grǎbnak)
• Catalan: raquis (ca) m
• Esperanto: rakio
• Romanian: rahis (ro) n
• Spanish: raquis (es) m

zoology: anatomical shaft or axis in a marine invertebrate

central shaft of a feather

• Bulgarian: стъбло (bg) n (stǎblo)
• Catalan: raquis (ca) m
• Finnish: ruoti (fi), ruoto (fi)
• Romanian: rahis (ro) n
• Spanish: raquis (es) m

main shaft of a compound leaf or head of grain

• Catalan: raquis (ca) m
• Finnish: keskiranka (compound leaf); lapakko (head of grain)
• Galician: raque (gl) m
• Romanian: rahis (ro) n
• Spanish: raquis (es) m

References

• “rachis”, in OneLook Dictionary Search.
• “rachis”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.

Anagrams

• Charis, Sirach, chairs