Definition: A "briefcase bomb" is a type of explosive device that is hidden inside a briefcase. It usually includes an explosive material and a timer that triggers the explosion after a certain amount of time.
In more complex discussions, you might refer to the motives behind using a briefcase bomb, such as terrorism or sabotage.
"Go off": This phrasal verb means to explode or to make a loud noise.
"Set off": This can mean to cause something to explode.
A "briefcase bomb" is a dangerous device hidden in a briefcase. It is important in discussions about safety and security.