The act or process of infiltrating, as of water into a porous substance, or of a fluid into the cells of an organ or part of the body. / The substance which has entered the pores or cavities of a body.

plural of infiltration

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

plural of infiltrator

present participle of infiltrate

simple past tense and past participle of infiltrate

Third-person singular simple present indicative form of infiltrate

(transitive, intransitive) To surreptitiously penetrate, enter or gain access to. / (transitive) To cause to penetrate in this way.

(pathology) Any undesirable substance or group of cells that has made its way into part of the body.

An infiltrator; a spy who covertly enters a territory or organisation. / A substance that penetrates an object to give it some property, such as waterproofing.