blaster
An energy-shooting gun, often a pistol. The name seems to have been popularized by Star Wars, compared to the classic term "raygun". Can fire laser, plasma, or more exotic kinds of energy instead of a solid bullet. Technically a railgun or "Gauss" weapon flinging a projectile through electromagnetism could be a blaster, though the projectile itself isn't made of energy.
https://en.wikipedia.org/wiki/Blaster
https://en.wikipedia.org/wiki/Blaster_(Star_Wars)