Intergalactic

"Intergalactic" refers to anything involving or occurring between different galaxies, which are massive systems of stars, gas, and dust bound together by gravity. Our galaxy, the Milky Way, is just one of billions in the universe. The term often appears in science fiction to describe travel, communication, or activity spanning these vast cosmic distances. Because galaxies are incredibly far apart—millions to billions of light-years—intergalactic phenomena deal with immense scales, requiring advanced technology and understanding of physics. Essentially, "intergalactic" contextualizes the vast, universe-wide relationships beyond our own galaxy.