flatness

/ˈflætnəs/

//ˈflætnəs// noun

By · According to Wiktionary data (CC BY-SA) ·

"flatness" is a 8-letter English headword indexed on PlainSpell.

The verdict

“flatness” is uncommon English (frequency #58,695 among 2,507 “F” headwords), classed as a noun. The kind of spelling people second-guess.

#58,695
frequency rank, English
2,507
“F” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The state of being flat

Corpus desk

Index EN-flatness · flatness · English

flatness · rank #58,695 · 0 variants · 0 confusables

  • FREQ-RARE #58,695
  • LEN-LONG 8 letters
  • VOW-2 2 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 2,507
  • PHOTO-FINISH flaxseed

Nearest frequency peer: flaxseed (+1 rank slots)

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.

Frequency neighbourhood for “flatness”

Lower corpus rank = more everyday usage (inverted bar length for readability)

corpus weight

What this shows Bars show where “flatness” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for flatness
PropertyValue
Headwordflatness
LanguageEnglish
Part of speechNoun
IPA/ˈflætnəs/
Letters8
Frequency rank#58,695
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “flatness” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).flatnesslands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Ticks step logarithmically, so each one marks a roughly tenfold drop in how often the word turns up. Same rarity band neighbours include “flaxseed” (#58,696), “filmography” (#58,693), “flayed” (#58,697). Source: FrequencyWords open word-frequency list.

Rare enough to double-check

flatness is uncommon English at frequency #58,695 among 2,507 “F” headwords, classed as anoun, transcribed /ˈflætnəs/. Rarity is why readers land here mid-draft. 6 senses are on record.

flatness doesn't appear in our generated misspelling index, a sign its spelling follows regular English conventions. It is not paired with a close-neighbour confusable in our dataset, which tends to mean the word is visually distinctive enough to stand on its own.

Etymologically, the entry records: From Middle English flatnesse, equivalent to flat + -ness. The correct English form is flatness, spelled F-L-A-T-N-E-S-S.

Definition

  1. 1
    The state of being flat
  2. 2
    The state of being two-dimensional; planar : planarity
  3. 3
    The state of being bland : dullness
  4. 4
    Mattness, the quality of a painted surface which scatters or absorbs the light falling on it, so as to be substantially free from gloss or sheen
  5. 5
    Lack of bouquet and freshness of a wine, through too much aeration or infection with film yeasts
  6. 6
    slim-tailedness or platykurtosis.

Recorded use

Wiktionary example

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

  1. The flatness of the landscape facilitates views right across the Firth of Forth to Fife, before the railway begins to pierce the Edinburgh suburbs.

Etymology

From Middle English flatnesse, equivalent to flat + -ness.

This word in other languages

aburrición(Español)planéité(Français)

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

How do you spell "flatness"?
"flatness" is spelled F-L-A-T-N-E-S-S. The IPA pronunciation is /ˈflætnəs/.
What does "flatness" mean?
As a noun, "flatness" means: The state of being flat
How do you pronounce "flatness"?
The IPA (International Phonetic Alphabet) transcription for "flatness" is /ˈflætnəs/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "flatness"?
From Middle English flatnesse, equivalent to flat + -ness. See the full etymology section above for more details.
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.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "flatness", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 8 letters (nearest by frequency rank).

flaxseed#58,696farmyard#58,685freemium#58,707futurity#58,712

What to do next

You've looked up "flatness". Here's where to go from here.

  • Usage frequency rank #58,695 among English headwords in this corpus. Corpus statistics
  • Browse more English words in the "F" letter cohort. F–Z browse
  • PlainSpell rotates a curated Word of the Day from the English corpus, a passive way to discover vocabulary. Word of the Day

PlainSpell is a reference corpus, not spelling advice. Verify unusual forms in context.

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.

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

Source: FrequencyWords open word-frequency list