Laser
From Tardis Wiki, the free Doctor Who reference
A laser was an artificial beam of light that travels in a single direction direction. Many lasers were harmless and used in some games (SJA: Warriors of Kudlak), but other lasers were used as deadly weapons.
Some weapons, such as Sontaran lasers, were called "lasers" despite travelling slower than light. (DW: The Sontaran Strategem)