Infiltrate \In*fil"trate\, v. i. [imp. & p. p. {Infiltrated}; p. pr. & vb. n. {Infiltrating}.] [Pref. in- + filtrate: cf. F, s'infiltrer. Cf. {Infilter}.] To enter by penetrating the pores or interstices of a substance; to filter into or through something. The water infiltrates through the porous rock. --Addison.