Did you dream about flamethrowers? To see or use a flamethrower in the dream refers to destructive words that you or someone yields. These destructive words are the fire that has the power to deal with permanent damage. Learn about more detailed interpretation here. For example, if someone uses a flamethrower to burn you specifically, the dreams refer to some plot against you.
If you use the flamethrower gun to burn off the grass in the dream, that relates to the flame-thrower is burning his bridges and connections with people surrounding him. The destructive words are stupid and ignorant that will cause long-lasting damage.