[101stAirborneVet]

I'd bet you my house a "verbal threat" of grievous bodily injury or death could justify use of lethal force, in nearly ANY jurisdiction.

It would have to accompany an actual perception on the part of the user of force that the speaker had the means and intent to carry out the threat in the language.

If I said to you, "I'm going to put your head in a blender and turn it on the highest setting", unless I am carrying a presently operable blender and appear sincere in my threat, you probably shouldn't use deadly force. An extreme example, I know, but it illustrates the point.

[Trailerpark Badass]

Yes, the legal requirement, generally, is that the threat would reasonably be considered credible, with reasonableness being determined by a jury.

That said, if a teenage punk says, "I got a gun, and I'm gonna shoot your ass," you are not required to wait around and see if he actually pulls out a gun and shoots you before you can use deadly force.

Such is the problem with teenage bravado.