sea urchin
/ˈsi ˌɝtʃɪ̈n/
"sea-urchin" is a 9-letter English headword indexed on PlainSpell.
The verdict
“sea urchin” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 10
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Any of many marine echinoderms, of the class Echinoidea, commonly found in shallow water, having a complex chewing structure named Aristotle's lantern.
Corpus desk
Index EN-sea-urchin · sea urchin · English
sea urchin · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-MEGA 10 letters
- VOW-4 4 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "S" thin
- PHOTO-UNK Peer pending
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.
| Property | Value |
|---|---|
| Headword | sea urchin |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈsi ˌɝtʃɪ̈n/ |
| Letters | 10 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “sea urchin” in English
Rare enough to double-check
sea urchin is uncommon English outside the top frequency list, classed as anoun, transcribed /ˈsi ˌɝtʃɪ̈n/. Rarity is why readers land here mid-draft. Gloss: "Any of many marine echinoderms, of the class Echinoidea, commonly found in shallow water, having a complex chewing structure named Aristotle's lantern.".
Our edit-distance generator produced no likely misspellings for sea urchin, a sign its spelling follows regular English conventions. Our confusable-pair dataset has no match for it, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.
Etymologically, the entry records: From sea + urchin (“hedgehog”), reflecting a similarity in appearance to a hedgehog. The correct English form is sea urchin, spelled S-E-A- -U-R-C-H-I-N.
Definition
- 1Any of many marine echinoderms, of the class Echinoidea, commonly found in shallow water, having a complex chewing structure named Aristotle's lantern.
Recorded use
Wiktionary examplesThese source excerpts show how sea urchin appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
1986, Patrick S. Leahy, Chapter 1: Laboratory Culture of Strongylocentrotus purpuratus Adults, Embryos, and Larvae, Thomas E. Schroeder (editor), Methods in Cell Biology, Volume 27: Echinoderm Gametes and Embryos, page 2, Of the many species of sea urchins utilized in biological research today the most widely used in North America is probably the purple s…
The pericentriolar radial complex characteristic of the spermatozoa of other echinoderms is lacking in the spermatozoa of all sea urchins.
Etymology
From sea + urchin (“hedgehog”), reflecting a similarity in appearance to a hedgehog.
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). See the methodology for how each field is sourced and updated.