regolith
/ˈɹɛɡəlɪθ/
"regolith" is a 8-letter English headword indexed on PlainSpell.
The verdict
“regolith” is uncommon English (frequency #78,070 among 21,470 “R” headwords), classed as a noun. The kind of spelling people second-guess.
- #78,070
- frequency rank, English
- 21,470
- “R” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The layer of loose rock, dust, sand, and soil, resting on the bedrock, that constitutes the surface layer of most dry land on Earth, the Moon, and other large solid aggregated celestial objects. Su...
| Property | Value |
|---|---|
| Headword | regolith |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈɹɛɡəlɪθ/ |
| Letters | 8 |
| Frequency rank | #78,070 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “regolith” sits in English frequency
Rare enough to double-check
regolith is uncommon English at frequency #78,070 among 21,470 “R” headwords, classed as anoun, transcribed /ˈɹɛɡəlɪθ/. Rarity is why readers land here mid-draft. Gloss: "The layer of loose rock, dust, sand, and soil, resting on the bedrock, that constitutes the surface layer of most dry land on Earth, the Moon, and other large solid aggregated celestial objects. Su...".
regolith doesn't appear in our generated misspelling index, since its letter sequence doesn't invite the usual edit-distance slips. No confusable counterpart is on file for this word, since no other headword is close enough in sound or shape to pair with it.
Etymologically, the entry records: Irregular formation from Ancient Greek ῥῆγος (rhêgos, “rug, blanket”) + -lith (from λίθος (líthos, “stone”)). The correct English form is regolith, spelled R-E-G-O-L-I-T-H.
Definition
- 1The layer of loose rock, dust, sand, and soil, resting on the bedrock, that constitutes the surface layer of most dry land on Earth, the Moon, and other large solid aggregated celestial objects. Submarine regolith also exists.
Etymology
Irregular formation from Ancient Greek ῥῆγος (rhêgos, “rug, blanket”) + -lith (from λίθος (líthos, “stone”)).
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
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Using “regolith”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is R-E-G-O-L-I-T-H - every other letter order is a misspelling in standard orthography.
- Say it as /ˈɹɛɡəlɪθ/ (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.