unidentified flying object
"unidentified-flying-object" is a 24-letter English headword indexed on PlainSpell.
The verdict
“unidentified flying object” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 26
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Anything not readily explainable appearing to move through or be suspended in the air.
| Property | Value |
|---|---|
| Headword | unidentified flying object |
| Language | English |
| Part of speech | Noun |
| Letters | 26 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “unidentified flying object” sits in English frequency
Rare enough to double-check
unidentified flying object is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. 3 senses are on record.
No misspelling variants are generated for unidentified flying object in our index, and the word's spelling is regular enough that our generator found nothing worth flagging. This headword has no recorded confusable partner, which typically means the spelling is too distinctive to be mistaken for another word.
Etymologically, the entry records: The phrase is usually attributed to US Air Force officer Edward J. Ruppelt (1923–1960) who coined it as a replacement of the terms flying saucer and flying disk. The correct English form is unidentified flying object, spelled U-N-I-D-E-N-T-I-F-I-E-D- -F-L-Y-I-N-G- -O-B-J-E-C-T.
Definition
- 1Anything not readily explainable appearing to move through or be suspended in the air.
- 2Anything not readily explainable appearing to move through or be suspended in the air.
- 3An alien spacecraft.
Etymology
The phrase is usually attributed to US Air Force officer Edward J. Ruppelt (1923–1960) who coined it as a replacement of the terms flying saucer and flying disk.
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 “unidentified flying object”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is U-N-I-D-E-N-T-I-F-I-E-D- -F-L-Y-I-N-G- -O-B-J-E-C-T - 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.