'''infiltration''' may refer science medicine engineering infiltration hydrology downward movement water soil infiltration hvac heating ventilation air conditioning term air leakage buildings infiltration medical diffusion accumulation substances cells normal amounts excess normal infiltration inflow leakage groundwater sanitary sewers uses entryism infiltration political organisation another usually larger organisation espionage using double agents join enemy organization infiltration tactics tactics developed german army early broke trench warfare stalemate
Applied science Military sciences Tactics Infiltration