Wiktionary
n. Any weapon that travels through space to a target either in space, in the atmosphere or on the ground
Wikipedia
Space weapons are weapons used in space warfare. They include weapons that can attack space systems in orbit (i.e. anti-satellite weapons), attack targets on the earth from space or disable missiles travelling through space. In the course of the militarisation of space, such weapons were developed mainly by the contesting superpowers during the Cold War, and some remain under development today. Space weapons are also a central theme in military science fiction and sci-fi video games.
Usage examples of "space weapon".
This was a win/lose proposition, the damage from a space weapon would rarely be wounding.
As negotiations break down, the Hobor leader shows they have a powerful ground - to - space weapon.