From Wiktionary, the free dictionary
From multi- + planetary.
multiplanetary (not comparable)
- Consisting of multiple planets.
2016, Priyamvada Natarajan, Mapping the Heavens: The Radical Scientific Ideas That Reveal the Cosmos[1]:As of November 10, 2015, more than 5,000 exoplanets have been discovered, some of them in the 484 known multiplanetary systems.
