The Collaborative International Dictionary of English v.0.48:

Eavesdropping \Eaves"drop`ping\, n. (Law)
   The habit of lurking about dwelling houses, and other places
   where persons meet for private intercourse, secretly
   listening to what is said, and then tattling it abroad. The
   offense is indictable at common law. --Wharton.
   [1913 Webster]