regex

/ˈɹɛɡˌɛks/

//ˈɹɛɡˌɛks// noun

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

"regex" is a 5-letter English headword indexed on PlainSpell.

The verdict

“regex” is uncommon English (frequency #77,133 among 3,094 “R” headwords), classed as a noun. The kind of spelling people second-guess.

#77,133
frequency rank, English
3,094
“R” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Clipping of regular expression.

Corpus desk

Index EN-regex · regex · English

regex · rank #77,133 · 0 variants · 0 confusables

  • FREQ-RARE #77,133
  • LEN-MID 5 letters
  • VOW-2 2 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 3,094
  • PHOTO-FINISH reeducation

Nearest frequency peer: reeducation (-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.

Long-tail ranks near “regex”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “regex” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for regex
PropertyValue
Headwordregex
LanguageEnglish
Part of speechNoun
IPA/ˈɹɛɡˌɛks/
Letters5
Frequency rank#77,133
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “regex” in English

This scale runs from the tiny cluster of words that carry ordinary speech (left) to the long tail of words almost nobody reaches for (right).regexfalls in this rarity band:

#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. Rare peers in the same band: “reeducation” (#77,132), “rectitude” (#77,130), “recordkeeping” (#77,129). Among 3,094 “R” headwords, “regex” is #77,133. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

regex is uncommon English at frequency #77,133 among 3,094 “R” headwords, classed as anoun, transcribed /ˈɹɛɡˌɛks/. Rarity is why readers land here mid-draft. Gloss: "Clipping of regular expression.".

No generated misspelling entries exist for regex in our index, which points to an orthography that plays by predictable English rules. This entry stands alone in our confusable dataset, since no other headword is close enough in sound or shape to pair with it.

This entry's etymology isn't recorded, leaving phoneme-to-grapheme mapping as the best guide to its spelling rather than a borrowing history. The correct English form is regex, spelled R-E-G-E-X.

Definition

  1. 1
    Clipping of regular expression.

Recorded use

Wiktionary example

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

  1. To continue the history course from the previous section, Perl was one of the first general-purpose programming languages to bake regexes into its core functionality.

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 "regex"?
"regex" is spelled R-E-G-E-X. The IPA pronunciation is /ˈɹɛɡˌɛks/.
What does "regex" mean?
As a noun, "regex" means: Clipping of regular expression.
How do you pronounce "regex"?
The IPA (International Phonetic Alphabet) transcription for "regex" is /ˈɹɛɡˌɛks/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "regex" come from?
"regex" is a English word. PlainSpell's reference spans five languages -- English, Spanish, Portuguese, French, and German -- with definitions, pronunciations, and spelling data for each.
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 "regex", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 5 letters (nearest by frequency rank).

Renny#77,138Petre#77,084peavy#77,077pathe#77,074

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

Source: FrequencyWords open word-frequency list