noun · verb · 12 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
UK:/ˈɪnfɪltɹeɪt/
US:/ˈɪnfəltɹeɪt/
US:/ɪnˈfɪltɹeɪt/
US:Recorded audio is listed in the source snapshot.
CMU ARPABET:IH1 N F IH0 L T R EY2 T
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
noun
Meaning 1
Any undesirable substance or group of cells that has made its way into part of the body.
Definition source: English Wiktionary via Wiktextract
Topics: medicine, pathology, sciences
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
2
verb
Meaning 2
To surreptitiously penetrate, enter or gain access to.
Definition source: English Wiktionary via Wiktextract
Usage: ambitransitive
Examples
The spy infiltrated the high-tech company and stole many secrets.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
3
verb
Meaning 3
To cause to penetrate in this way.
Definition source: English Wiktionary via Wiktextract
Usage: transitive
Examples
The agency infiltrated several spies into the company.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
4
verb
Meaning 4
To pass through something by filtration.
Definition source: English Wiktionary via Wiktextract
Usage: ambitransitive
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
5
verb
Meaning 5
To cause (a liquid) to pass through something by filtration.
Definition source: English Wiktionary via Wiktextract
Usage: transitive
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
6
verb
Meaning 6
To invade or penetrate a tissue or organ.
Definition source: English Wiktionary via Wiktextract
Usage: ambitransitive
Topics: medicine, sciences
Examples
High-grade tumors often infiltrate surrounding structures.
In certain conditions, immune cells may infiltrate into the cerebrospinal fluid.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
7
verb
Meaning 7
To send (soldiers, spies, etc.) through gaps in the enemy line.
Definition source: English Wiktionary via Wiktextract
Usage: transitive
Topics: government, military, politics, war
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: exfiltrate
8
verb
Meaning 8
To move from a vein, remaining in the body.
Definition source: English Wiktionary via Wiktextract
Usage: intransitive
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
9
verb
Meaning 9
pass through an enemy line; in a military conflict
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: pass through
Antonyms: none provided
Broader terms: pass, go through, go across
10
verb
Meaning 10
pass into or through by filtering or permeating
Definition source: Princeton WordNet 3.0
Examples
the substance infiltrated the material
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: percolate, sink in, permeate, filter
11
verb
Meaning 11
cause (a liquid) to enter by penetrating the interstices
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: percolate, sink in, permeate, filter
12
verb
Meaning 12
enter a group or organization in order to spy on the members
Definition source: Princeton WordNet 3.0
Examples
The student organization was infiltrated by a traitor
Meaning relationships
Synonyms: penetrate
Antonyms: none provided
Broader terms: join, fall in, get together
History
Etymology
From Middle English infiltrate (adjective), from Medieval Latin infiltrātus, from infiltrō.
Across languages
Translations
55 source translations are retained for this English entry.
German:
Infiltrat
— infiltrate
Hungarian:
infiltrátum
— infiltrate
Hungarian:
beszűrődés
— infiltrate
Indonesian:
infiltrat
— infiltrate
Romanian:
infiltrat
— infiltrate
Afrikaans:
infiltreer
— to surreptitiously penetrate, enter or gain access
Catalan:
infiltrar
— to surreptitiously penetrate, enter or gain access
Czech:
proniknout
— to surreptitiously penetrate, enter or gain access
Esperanto:
infiltri
— to surreptitiously penetrate, enter or gain access
Finnish:
soluttautua
— to surreptitiously penetrate, enter or gain access
French:
infiltrer
— to surreptitiously penetrate, enter or gain access
German:
infiltrieren
— to surreptitiously penetrate, enter or gain access
German:
unterwandern
— to surreptitiously penetrate, enter or gain access
Greek:
διεισδύω
(dieisdýo)
— to surreptitiously penetrate, enter or gain access
Hindi:
घुसपैठ करना
(ghuspaiṭh karnā)
— to surreptitiously penetrate, enter or gain access
Hindi:
पैठना
(paiṭhnā)
— to surreptitiously penetrate, enter or gain access
Hungarian:
beszivárog
— to surreptitiously penetrate, enter or gain access
Ido:
infiltrigar
— to surreptitiously penetrate, enter or gain access
Irish:
insíothlaigh
— to surreptitiously penetrate, enter or gain access
Irish:
síothlaigh isteach
— to surreptitiously penetrate, enter or gain access
Italian:
infiltrare
— to surreptitiously penetrate, enter or gain access
Japanese:
潜入する
(sennyū suru)
— to surreptitiously penetrate, enter or gain access
Māori:
ngoto
— to surreptitiously penetrate, enter or gain access
Persian:
نفوذ کردن
(nofuz kardan)
— to surreptitiously penetrate, enter or gain access
Russian:
проса́чиваться
(prosáčivatʹsja)
— to surreptitiously penetrate, enter or gain access
Russian:
просочи́ться
(prosočítʹsja)
— to surreptitiously penetrate, enter or gain access
Russian:
проника́ть
(pronikátʹ)
— to surreptitiously penetrate, enter or gain access
Russian:
прони́кнуть
(proníknutʹ)
— to surreptitiously penetrate, enter or gain access
Sicilian:
nfirtrari
— to surreptitiously penetrate, enter or gain access
Spanish:
infiltrarse
— to surreptitiously penetrate, enter or gain access
Swedish:
infiltrera
— to surreptitiously penetrate, enter or gain access
Thai:
แทรกซึม
— to surreptitiously penetrate, enter or gain access
Bulgarian:
процеждам
(proceždam)
— to cause a fluid to pass through a substance by filtration
Bulgarian:
просмуквам се
(prosmukvam se)
— to cause a fluid to pass through a substance by filtration
Catalan:
infiltrar
— to cause a fluid to pass through a substance by filtration
Finnish:
suodattaa
— to cause a fluid to pass through a substance by filtration
Irish:
insíothlaigh
— to cause a fluid to pass through a substance by filtration
Irish:
síothlaigh isteach
— to cause a fluid to pass through a substance by filtration
Italian:
filtrare
— to cause a fluid to pass through a substance by filtration
Japanese:
浸透させる
(shintō saseru)
— to cause a fluid to pass through a substance by filtration
Manx:
yn-heel
— to cause a fluid to pass through a substance by filtration
Sicilian:
firtrari
— to cause a fluid to pass through a substance by filtration
Spanish:
infiltrar
— to cause a fluid to pass through a substance by filtration
Turkish:
süzmek
— to cause a fluid to pass through a substance by filtration
Belarusian:
пранікаць у тыл праціўніка
(pranikacʹ u tyl praciwnika)
— to send soldiers through gaps in the enemy line
Belarusian:
пранікнуць у тыл праціўніка
(praniknucʹ u tyl praciwnika)
— to send soldiers through gaps in the enemy line
Finnish:
soluttaa
— to send soldiers through gaps in the enemy line
Italian:
infiltrare
— to send soldiers through gaps in the enemy line
Japanese:
潜入させる
(sennyū saseru)
— to send soldiers through gaps in the enemy line
Polish:
infiltrować
— to send soldiers through gaps in the enemy line
Polish:
zinfiltrować
— to send soldiers through gaps in the enemy line
Russian:
проникать в тыл противника
(pronikatʹ v tyl protivnika)
— to send soldiers through gaps in the enemy line
Russian:
проникнуть в тыл противника
(proniknutʹ v tyl protivnika)
— to send soldiers through gaps in the enemy line
Sicilian:
nfirtrari
— to send soldiers through gaps in the enemy line
Thai:
สอดแทรก
— to send soldiers through gaps in the enemy line