*filtrat*

n. That which has been filtered; the liquid which has passed through the filter in the process of filtration. Contrasted with retentate, the material remaining on the filter. [ 1913 Webster ]

n. [ Cf. F. filtration. ] The act or process of filtering; the mechanical separation of a liquid from the undissolved particles floating in it.

v. i. [ imp. & p. p. Infiltrated p. pr. & vb. n. Infiltrating ] [ Pref. in- + filtrate: cf. F, s'infiltrer. Cf. Infilter. ] 1. To enter by penetrating the pores or interstices of a substance; to filter into or through something. [ 1913 Webster ]

The water infiltrates through the porous rock. Addison. [ 1913 Webster ]

2. To enter secretly (into an organization, territory, etc.) for hostile purposes, such as spying or sabotage; as, the FBI infiltrated into the U. S. communist party's upper echelons; also used transitively; as, to infiltrate the opponent's organization; to infiltrate one's agents into a hostile country. [ PJC ]

v. t. To penetrate gradually; -- sometimes used reflexively. J. S. Mill. [ 1913 Webster ]

n. [ Cf. F. infiltration. ] [ 1913 Webster ]

1. The act or process of infiltrating, as of water into a porous substance, of a fluid into the cells of an organ or part of the body, or of persons into a hostile organization. [ 1913 Webster +PJC ]

2. The substance which has entered the pores or cavities of a body. Addison. [ 1913 Webster ]

Calcareous infiltrations filling the cavities. Kirwan. [ 1913 Webster ]

Fatty infiltration. (Med.) See under Fatty. --
Infiltration gallery, a filter gallery. [ 1913 Webster ]