rachis

/ˈɹeɪkɪs/

//ˈɹeɪkɪs// noun

"rachis" is a 6-letter English headword indexed on PlainSpell.

The verdict

“rachis” is uncommon English (frequency #94,161 among 3,094 “R” headwords), classed as a noun. The kind of spelling people second-guess.

#94,161
frequency rank, English
3,094
“R” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The spinal column, or the vertebrae of the spine.

Corpus desk

Index EN-rachis · rachis · English

rachis · rank #94,161 · 0 variants · 0 confusables

  • FREQ-RARE #94,161
  • LEN-LONG 6 letters
  • VOW-2 2 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 3,094
  • PHOTO-FINISH quisling

Nearest frequency peer: quisling (-2 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Long-tail ranks near “rachis”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “rachis” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for rachis
PropertyValue
Headwordrachis
LanguageEnglish
Part of speechNoun
IPA/ˈɹeɪkɪs/
Letters6
Frequency rank#94,161
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “rachis” in English

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).rachisfalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Rare peers in the same band: “quisling” (#94,159), “quieten” (#94,158), “quetzal” (#94,157). Among 3,094 “R” headwords, “rachis” is #94,161. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

rachis is uncommon English at frequency #94,161 among 3,094 “R” headwords, classed as anoun, transcribed /ˈɹeɪkɪs/. Rarity is why readers land here mid-draft. 4 senses are on record.

Our edit-distance generator produced no likely misspellings for rachis, typically a sign the spelling maps closely to how the word sounds. No close-neighbour confusable shows up for this headword in our dataset, since nothing in our dataset looks or sounds close enough to cause mix-ups.

Etymologically, the entry records: From New Latin rachis, from Ancient Greek ῥάχις (rhákhis, “spine, ridge”). The correct English form is rachis, spelled R-A-C-H-I-S.

Definition

  1. 1
    The spinal column, or the vertebrae of the spine.
  2. 2
    An anatomical shaft or axis in a marine invertebrate.
  3. 3
    The central shaft of a feather.
  4. 4
    The axis of either a compound leaf, inflorescence, or fern frond.

Recorded use

Wiktionary example

These source excerpts show how rachis appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. 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.

Etymology

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

This word in other languages

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "rachis"?
"rachis" is spelled R-A-C-H-I-S. The IPA pronunciation is /ˈɹeɪkɪs/.
What does "rachis" mean?
As a noun, "rachis" means: The spinal column, or the vertebrae of the spine.
How do you pronounce "rachis"?
The IPA (International Phonetic Alphabet) transcription for "rachis" is /ˈɹeɪkɪs/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "rachis"?
From New Latin rachis, from Ancient Greek ῥάχις (rhákhis, “spine, ridge”). See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "rachis", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 6 letters (nearest by frequency rank).

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list