/dē-ˌfe-nə-ˈstrā-shən/
[from the traditional Czechoslovak method of assassinating prime ministers, via SF fandom]
n. 1. Proper karmic retribution for an incorrigible punster.
"Oh, ghod, that was *awful*!"
"Quick! Defenestrate him!"
2. The act of exiting a window system in order to get better response time from a full-screen program. This comes from the dictionary meaning of 'defenestrate', which is to throw something out a window.
3. The act of discarding something under the assumption that it will improve matters.