keystone

/ˈkiː.stəʊn/

//ˈkiː.stəʊn// noun

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

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

The verdict

“keystone” is a moderately-common English word, ranked #16,057 in English word frequency and used as a noun.

#16,057
frequency rank, English
8
letters
12
tracked misspellings
1
confusable pair

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The top stone of an arch.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

keystone vs ketone
75% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for keystone
PropertyValue
Headwordkeystone
LanguageEnglish
Part of speechNoun
IPA/ˈkiː.stəʊn/
Letters8
Frequency rank#16,057
Misspellings tracked12
Confusable pairs1
SourceWiktionary (kaikki.org)

Where “keystone” 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). keystone lands here:

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

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The English entry for keystone is 8 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈkiː.stəʊn/. Corpus data places it at rank #16,057 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 5 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 12 likely wrong-spelling variants for keystone, with forms such as "ekystone", "kesytone", and "keysotne". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. It also participates in 1 confusable-pair relationship, "ketone", where similar look or sound leads writers to substitute one word for another in context.

Etymologically, the entry records: From key + stone. Definition 4 (retail) possibly originated in the jewelry industry in the magazine called "Jewelers' Circular-Keystone". The correct English form is keystone, spelled K-E-Y-S-T-O-N-E.

Definition

  1. 1
    The top stone of an arch.
  2. 2
    Something on which other things depend for support.
  3. 3
    A native or resident of the American state of Pennsylvania.
  4. 4
    A retail price that is double the cost price; a markup of 100%.
  5. 5
    The combination of the shortstop and second baseman.

Etymology

From key + stone. Definition 4 (retail) possibly originated in the jewelry industry in the magazine called "Jewelers' Circular-Keystone".

This word in other languages

clave(Español)clef de voûte(Français)Schlussstein(Deutsch)

Common misspellings

Also misspelled as: ekystone,kesytone,keysotne,keysstone,keystnoe,keystoen,keystonne,keysttone,keytsone,keyystone,kkeystone,kyestone

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of keystone - counted as single-character edits (an insertion, a deletion, or a substituted letter). The larger the bar, the easier the typo is to spot; one-edit slips are the ones that sneak past readers.

ekystone2kesytone2keysotne2keysstone1keystnoe2keystoen2keystonne1keysttone1
Edit distance from "keystone"

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 "keystone"?
"keystone" is spelled K-E-Y-S-T-O-N-E. The IPA pronunciation is /ˈkiː.stəʊn/.
What does "keystone" mean?
As a noun, "keystone" means: The top stone of an arch.
What words are commonly confused with "keystone"?
"keystone" is commonly confused with "ketone". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "keystone"?
The IPA (International Phonetic Alphabet) transcription for "keystone" is /ˈkiː.stəʊn/. 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 "keystone"?
From key + stone. Definition 4 (retail) possibly originated in the jewelry industry in the magazine called "Jewelers' Circular-Keystone". 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.

Using “keystone”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is K-E-Y-S-T-O-N-E - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈkiː.stəʊn/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “ketone” - see the side-by-side comparison. keystone vs ketone
  • 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.

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

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list