What does "infiltrator" mean?

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

What is a synonym for "infiltrator"?

Common synonyms include: buttinsky, gate crasher, informant, informant, intruder, narc.

Pronounced //ˈɪnfɪltɹeɪtə//.

//ˈɪnfɪltɹeɪtə// noun

noun ·Rare ·Advanced level

Noun

1
One who infiltrates an organization or territory; an undercover or covert agent.
"Sometimes Israelis were attacked by Arab infiltrators, and hardly a month went by without a West Jerusalemite either being killed or wounded."
2
an intruder (as troops) with hostile intent wordnet
3
someone who takes up a position surreptitiously for the purpose of espionage wordnet

"Sometimes Israelis were attacked by Arab infiltrators, and hardly a month went by without a West Jerusalemite either being killed or wounded."

From infiltrate + -or.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.