tunnel boring machine
"tunnel-boring-machine" is a 19-letter English headword indexed on PlainSpell.
The verdict
“tunnel boring machine” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 21
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A large machine used to excavate tunnels with a circular cross section.
| Property | Value |
|---|---|
| Headword | tunnel boring machine |
| Language | English |
| Part of speech | Noun |
| Letters | 21 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “tunnel boring machine” sits in English frequency
Rare enough to double-check
tunnel boring machine is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "A large machine used to excavate tunnels with a circular cross section.".
We couldn't generate a plausible misspelling set for tunnel boring machine, since its letter sequence doesn't invite the usual edit-distance slips. Our dataset records no confusable match here, which typically means the spelling is too distinctive to be mistaken for another word.
Wiktionary doesn't record an etymology for this headword, so its spelling is best read as a straightforward mapping from sound to letter. The correct English form is tunnel boring machine, spelled T-U-N-N-E-L- -B-O-R-I-N-G- -M-A-C-H-I-N-E.
Definition
- 1A large machine used to excavate tunnels with a circular cross section.
Synonyms
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.
Frequently Asked Questions
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Using “tunnel boring machine”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is T-U-N-N-E-L- -B-O-R-I-N-G- -M-A-C-H-I-N-E - every other letter order is a misspelling in standard orthography.
- Browse more English words and confusable pairs in the same reference. English words
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.