flat out

/ˌflæt ˈaʊt/

//ˌflæt ˈaʊt// adj

"flat-out" is a 7-letter English headword indexed on PlainSpell.

The verdict

“flat out” is uncommon English (outside the top frequency list), classed as an adjective. The kind of spelling people second-guess.

Unranked
below top-frequency English
8
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Used other than figuratively or idiomatically: see flat, out.

Corpus desk

Index EN-flat-out · flat out · English

flat out · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-LONG 8 letters
  • VOW-3 3 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "F" thin
  • PHOTO-UNK Peer pending

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Key facts for flat out
PropertyValue
Headwordflat out
LanguageEnglish
Part of speechAdjective
IPA/ˌflæt ˈaʊt/
Letters8
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “flat out” in English

flat outfalls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

flat out is uncommon English outside the top frequency list, classed as anadjective, transcribed /ˌflæt ˈaʊt/. Rarity is why readers land here mid-draft. 4 senses are on record.

No misspelling variants are generated for flat out in our index, which points to an orthography that plays by predictable English rules. Our confusable-pair dataset has no match for it, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.

This entry carries no recorded etymology, so any spelling logic here comes from how the word's sounds map to letters, not a documented origin story. The correct English form is flat out, spelled F-L-A-T- -O-U-T.

Definition

  1. 1
    Used other than figuratively or idiomatically: see flat, out.
  2. 2
    Complete, total, downright.
  3. 3
    Very busy.
  4. 4
    Lazy, sleeping.

Recorded use

Wiktionary examples

These source excerpts show how flat out appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. So many of them took pictures, of themselves and of me, that we ran flat out of black-and-white film the second day out, and there wasn′t a Queen Mary necktie to be had in the shops after we left the port.
  2. Avoid Flat-Out Opposites The slob vs. the neatnik. The artist vs. the precision-freak. The freethinker vs. the tightass. Liberal vs. conservative. Jock vs. nerd. David vs. Goliath. Good vs. evil. Beauty and the Beast. Jekyll^([sic]) and Hyde.

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

How do you spell "flat out"?
"flat out" is spelled F-L-A-T- -O-U-T. The IPA pronunciation is /ˌflæt ˈaʊt/.
What does "flat out" mean?
As an adjective, "flat out" means: Used other than figuratively or idiomatically: see flat, out.
How do you pronounce "flat out"?
The IPA (International Phonetic Alphabet) transcription for "flat out" is /ˌflæt ˈaʊt/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "flat out" come from?
"flat out" is a English word. You can look up definitions, pronunciations, and spelling data for this and other words across English, Spanish, Portuguese, French, and German on PlainSpell.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list