Boom! To detonate is to explode or cause something to explode. If a bad guy lights the fuse of a stick of dynamite, run before it detonates!
In war, there is a lot of detonating, which is when something violently explodes, like bombs or grenades. When someone steps on a landmine, it detonates. The detonating of nuclear bombs devastated Hiroshima and Nagasaki at the end of World War II. Also, to detonate is to set off a bomb. Pushing a button, flicking a switch, or lighting a fuse could detonate a bomb. Either way, to detonate is to blow up.