What does infiltrated mean?
Infiltrated is the past tense and past participle of infiltrate, a verb meaning to enter secretly or without authorization. It is especially associated with spies, investigators, criminals, or other people who gain access to an organization or place while concealing their identity or purpose: undercover officers may infiltrate a criminal network, while a hacker may infiltrate a computer system. The word also has a less literal sense in which something spreads gradually into a group, institution, or area, as with “new ideas infiltrated the workplace.” In this use, the secrecy may be absent, though the word often suggests a slow or subtle process. The metaphorical and literal senses both preserve the underlying idea of passing into a space or structure that is normally protected or difficult to enter.
verbTo enter secretly or covertly, especially a group, organization, or controlled area. In a less formal sense, to gradually enter or spread through something.
- To enter secretly or covertly, especially for the purpose of gaining information, influence, or access.
- To enter, spread through, or come to permeate something gradually, especially as a social, political, or cultural influence.
- Past tense and past participle of infiltrate.
"The undercover agents infiltrated the organization and gathered evidence for several months."
"A journalist infiltrated the private meeting to learn more about the allegations."
"New ideas gradually infiltrated the classroom and changed the way students approached the subject."
The word comes from the idea of liquid passing through a filter, but its modern sense turns that image into a spy entering a group without being noticed.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does infiltrated come from?
Infiltrate derives from Latin infiltrāre, meaning “to filter in” or “to enter through a filter.” The word entered English in the early 19th century with the sense of passing a liquid through a filter, and it later developed the figurative meaning of entering a group or organization secretly. Related English forms include filter, filtrate, and filtration, all based on the same Latin root associated with filtering.
Related word forms
How infiltrated is actually used
The primary sense is covert or unauthorized entry, and it often carries a negative or clandestine connotation. The figurative sense can be neutral or positive, depending on what is spreading and whether it is welcomed.