railgun

/ˈɹeɪl.ɡʌn/

Etymology

From rail + gun. * (railway gun): From being a gun mounted on a rail car, and being railroad-mobile. * (EM gun): From being a projectile ejecting device with a pair of electric conducting rails that a launch sled runs along, which shoots the projectile.

noun

An electromagnetic gun that uses a large electrical current to propel a projectile down a track of two parallel conductive rails.
A railway gun.
A benchrest rifle.