protoplanetary

About 0.02 uses per million words.

Meaning

1. adjective Of or pertaining to a protoplanet.
2. adjective Relating to a stage in the life of a red giant star or its protoplanetary nebula during the star's final stages of life

Similar words

planetary planetic planetological planeted planetographic planetoidal protostellar planetlike planetical exoplanetary

Often followed by

disk disks cloud nebula disc nebulae accretion discs bodies systems