a weapon, particularly a handgun, which is kept hidden on one's person, or under one's control (in a glove compartment or under a car seat).
any gun, knife, sword, crossbow, slingshot or other weapon which can cause bodily harm to people (even though used for target shooting).
any weapon which can kill. This includes not only weapons which are intended to do harm like a gun or knife, but also blunt instruments like clubs, baseball bats, monkey wrenches, an automobile or any object which actually causes death. This becomes important when trying to prove criminal charges brought for assault with a deadly weapon. In a few 1990s cases courts have found rocks and even penises of AIDS sufferers as "deadly weapons."