infiltrator

/ˈɪnfɪltɹeɪtə/

//ˈɪnfɪltɹeɪtə// noun

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

"infiltrator" is a 11-letter English headword indexed on PlainSpell.

The verdict

“infiltrator” is uncommon English (frequency #77,797 among 2,140 “I” headwords), classed as a noun. The kind of spelling people second-guess.

#77,797
frequency rank, English
2,140
“I” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - One who infiltrates an organization or territory; an undercover or covert agent.

Corpus desk

Index EN-infiltrator · infiltrator · English

infiltrator · rank #77,797 · 0 variants · 0 confusables

  • FREQ-RARE #77,797
  • LEN-MEGA 11 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 2,140
  • PHOTO-FINISH ingroup

Nearest frequency peer: ingroup (+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 “infiltrator”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for infiltrator
PropertyValue
Headwordinfiltrator
LanguageEnglish
Part of speechNoun
IPA/ˈɪnfɪltɹeɪtə/
Letters11
Frequency rank#77,797
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “infiltrator” 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).infiltratorfalls 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: “ingroup” (#77,798), “incompressible” (#77,795), “inimical” (#77,799). Among 2,140 “I” headwords, “infiltrator” is #77,797. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

infiltrator is uncommon English at frequency #77,797 among 2,140 “I” headwords, classed as anoun, transcribed /ˈɪnfɪltɹeɪtə/. Rarity is why readers land here mid-draft. Gloss: "One who infiltrates an organization or territory; an undercover or covert agent.".

infiltrator doesn't appear in our generated misspelling index, suggesting the orthography follows predictable English patterns. No confusable counterpart is on file for this word, since no other headword is close enough in sound or shape to pair with it.

Etymologically, the entry records: From infiltrate + -or. The correct English form is infiltrator, spelled I-N-F-I-L-T-R-A-T-O-R.

Definition

  1. 1
    One who infiltrates an organization or territory; an undercover or covert agent.

Recorded use

Wiktionary examples

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

  1. Sometimes Israelis were attacked by Arab infiltrators, and hardly a month went by without a West Jerusalemite either being killed or wounded.
  2. Suddenly, one of the cadre appeared from out of the darkness. "Hello, soldier", he said. "Do you have a light?” “Sure,” Jack replied, digging into his pocket for a book of matches. “Soldier! You are dead!” exclaimed the cadre. Jack had failed to challenge the infiltrator. The password was “Bronx”, the counter password was “Bombers”.

Etymology

From infiltrate + -or.

Synonyms

informantnarcspyplantprovocateur

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 "infiltrator"?
"infiltrator" is spelled I-N-F-I-L-T-R-A-T-O-R. The IPA pronunciation is /ˈɪnfɪltɹeɪtə/.
What does "infiltrator" mean?
As a noun, "infiltrator" means: One who infiltrates an organization or territory; an undercover or covert agent.
How do you pronounce "infiltrator"?
The IPA (International Phonetic Alphabet) transcription for "infiltrator" is /ˈɪnfɪltɹeɪtə/. 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 "infiltrator"?
From infiltrate + -or. 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 "infiltrator", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 11 letters (nearest by frequency rank).

iridescence#77,806hypermarket#77,782heartedness#77,753headmasters#77,752

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

Source: FrequencyWords open word-frequency list