1. (military) the process of exiting an area (usually in enemy territory)
   "The special forces team planned their exfiltration route carefully"
    
2. (computing) covert extraction of data, typically by unauthorized means such as hacking or malware
   "The cybersecurity team detected an exfiltration of sensitive customer data"
    
3. A process of filtering or seeping out
   "The slow exfiltration of groundwater through the soil layers"

Derived forms: exfiltrations

Encyclopedia: Exfiltration