2.) To take a life in self-defense. It is okay to kill somebody or something if you are being attacked by them.
3.) To inflict fatal casualties (kills and mortal wounding) during a war. In this situation, it may also combine with self-defense.
2.) The criminal was running onto Jim's lawn with guns drawn, so he blasted him with his 12-gauge.
3.) The Union infantry private participated in firing musket volleys into the attacking Confederates at the Battle of Shiloh.