Alibi, in law, a defense made by the accused in a criminal case. The word alibi is Latin for “elsewhere.” The accused tries to establish that at the time the crime was committed he or she was at some place other than where it was committed.
Maybe you're an escaped criminal or an undercover spy. You're someone who needs to stay under the radar. What you need is a safe house.
The U.S. was quick to denounce 9/11 as an act of terrorism. Drawing the line between mass murder and terrorism isn't always that straightforward though.