Directly opposite:
* Intragalactic: This would refer to something within a single galaxy.
* Local: This suggests something confined to a smaller area, like a planet or solar system.
Depending on the context:
* Terrestrial: If referring to space travel, this means Earth-bound.
* National: If the context is political or social, this could mean restricted to a single nation.
* Provincial: This suggests a limited scope, perhaps geographically or intellectually.
* Domestic: This emphasizes something within a specific household or country.
The best antonym for "intergalactic" depends on the specific meaning you want to express.