What does infiltrator mean?
An infiltrator is someone who secretly gains access to an organization, place, or system, often by posing as a trusted member or using deception. The word is especially common in reporting and discussion of espionage, terrorism, organized crime, political disruption, and security breaches, where it implies that someone has entered a group or controlled area without authorization. It may also describe a person who has become embedded in an institution in order to influence its activities from within. Because “infiltrator” carries a strongly negative and often threatening connotation, it is usually unsuitable for neutral descriptions of ordinary visitors or participants unless secrecy and lack of authorization are important to the meaning. The related verb is “infiltrate,” while the process or result is called an “infiltration.”
nounA person who secretly enters or gains a position in a group, organization, place, or system, usually with unauthorized or improper intentions. The term is often used in contexts involving espionage, political subversion, or criminal infiltration.
- A person who secretly enters or infiltrates an organization, place, or system.
"Security officials identified the suspected infiltrator who had gained access to the organization."
"The report warned that an infiltrator had entered the restricted facility."
"Party members suspected that political infiltrators were manipulating local meetings."
The plural is used for more than one person who secretly enters or gains access to a group, place, or system.
"The agency said that several infiltrators had accessed the secure network."
An infiltrator wins access before anyone realizes the breach has happened.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does infiltrator come from?
The word “infiltrator” was formed in English from “infiltrate” with the suffix “-er,” meaning a person who performs the action. “Infiltrate” ultimately comes through French from Latin “infilrare,” meaning “to filter in,” with the prefix “in-” and a root related to filtering. The modern sense of entering secretly or gaining access to an organization developed from this earlier idea of passing into a place or group unnoticed.
Related word forms
How infiltrator is actually used
The word generally carries a negative and potentially accusatory connotation. It is used particularly in discussions of espionage, extremism, organized crime, security breaches, and political disruption, although it can also refer more neutrally to an unauthorized person who has entered a group.