unobservable
"unobservable" is a 12-letter English headword indexed on PlainSpell.
The verdict
“unobservable” is uncommon English (frequency #96,618 among 23,789 “U” headwords), classed as an adjective. The kind of spelling people second-guess.
- #96,618
- frequency rank, English
- 23,789
- “U” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - That cannot be observed.
| Property | Value |
|---|---|
| Headword | unobservable |
| Language | English |
| Part of speech | Adjective |
| Letters | 12 |
| Frequency rank | #96,618 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “unobservable” sits in English frequency
Rare enough to double-check
unobservable is uncommon English at frequency #96,618 among 23,789 “U” headwords, classed as anadjective. Rarity is why readers land here mid-draft. Gloss: "That cannot be observed.".
The misspelling generator found no plausible variants for unobservable, and the word's spelling is regular enough that our generator found nothing worth flagging. No close-neighbour confusable shows up for this headword in our dataset, since its spelling is unusual enough that it doesn't cluster with a lookalike.
Etymologically, the entry records: From un- + observable. The correct English form is unobservable, spelled U-N-O-B-S-E-R-V-A-B-L-E.
Definition
- 1That cannot be observed.
Etymology
From un- + observable.
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 “unobservable”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is U-N-O-B-S-E-R-V-A-B-L-E - every other letter order is a misspelling in standard orthography.
- 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.