tetrahedron
/ˌtɛtɹəˈhiːdɹən/
"tetrahedron" is a 11-letter English headword indexed on PlainSpell.
The verdict
“tetrahedron” is uncommon English (frequency #67,103 among 27,828 “T” headwords), classed as a noun. The kind of spelling people second-guess.
- #67,103
- frequency rank, English
- 27,828
- “T” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A polyhedron with four faces; the regular tetrahedron, the faces of which are equal equilateral triangles, is one of the Platonic solids.
| Property | Value |
|---|---|
| Headword | tetrahedron |
| Language | English |
| Part of speech | Noun |
| IPA | /ˌtɛtɹəˈhiːdɹən/ |
| Letters | 11 |
| Frequency rank | #67,103 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “tetrahedron” sits in English frequency
Rare enough to double-check
tetrahedron is uncommon English at frequency #67,103 among 27,828 “T” headwords, classed as anoun, transcribed /ˌtɛtɹəˈhiːdɹən/. Rarity is why readers land here mid-draft. Gloss: "A polyhedron with four faces; the regular tetrahedron, the faces of which are equal equilateral triangles, is one of the Platonic solids.".
No misspelling variants are generated for tetrahedron in our index, suggesting the orthography follows predictable English patterns. No confusable counterpart is on file for this word, a sign it's visually distinctive enough not to be mixed up with another word.
Etymologically, the entry records: From Ancient Greek τετράεδρον (tetráedron, “triangle-based pyramid”), from τετράεδρος (tetráedros), from τετράς (tetrás, “four”) + ἕδρα (hédra, “seat”). By surface analysis, tetra- + -hedron. The correct English form is tetrahedron, spelled T-E-T-R-A-H-E-D-R-O-N.
Definition
- 1A polyhedron with four faces; the regular tetrahedron, the faces of which are equal equilateral triangles, is one of the Platonic solids.
Etymology
From Ancient Greek τετράεδρον (tetráedron, “triangle-based pyramid”), from τετράεδρος (tetráedros), from τετράς (tetrás, “four”) + ἕδρα (hédra, “seat”). By surface analysis, tetra- + -hedron.
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 "tetrahedron"?
What does "tetrahedron" mean?
How do you pronounce "tetrahedron"?
What is the origin of the word "tetrahedron"?
Is PlainSpell free to use?
Using “tetrahedron”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is T-E-T-R-A-H-E-D-R-O-N - every other letter order is a misspelling in standard orthography.
- Say it as /ˌtɛtɹəˈhiːdɹən/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Browse more English words and confusable pairs in the same reference. English words
Other uncommon English words near this rank
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.