exfiltration

Noun

 * 1)  The process of exiting an area (usually behind enemy lines or in enemy territory).
 * 2)  A method for managing storm water runoff.
 * 3)  A filtering out (usually movement of a substance through a barrier).
 * 4)  A gradual movement of a substance to exterior (as through cell membrane to extracellular fluid or medium).
 * 5)  Covert extraction of data from a system.