Science, medicine, and engineering
* Infiltration (hydrology), downward movement of water into soil * Infiltration (HVAC), a heating, ventilation, and air conditioning term for air leakage into buildings * Infiltration (medical), the diffusion or accumulation of substances or cells not normal to it or in amounts in excess of the normal * Infiltration/Inflow, leakage of groundwater into sanitary sewersOther uses
* Entryism, the infiltration by a political organisation of another, usually larger, organisation *In espionage, using double agents to join an enemy organization * Infiltration tactics, tactics developed by the German army in early 1915 that broke the trench-warfare stalemate on the western front * Urban exploration, exploring parts of towns, etc. which are normally off-limits * ''Infiltration'' (zine), a popular urban exploration zine/website created by Jeff Chapman (Ninjalicious) * Seon-Woo Lee (born 1985), professional electronic sports players, specializing in fighting games, who plays under the alias Infiltration * ''Infiltration'' (2017 film), a Canadian film * Infiltration (2022 film), Russian war drama filmSee also
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