From proto- + galactic. <span class="searchmatch">protogalactic</span> (not comparable) Pertaining to a protogalaxy....
multigalactic nongalactic non-galactic pangalactic perigalactic pregalactic <span class="searchmatch">protogalactic</span> subgalactic supergalactic transgalactic galaxy (medicine) pertaining...
protofilament Proto-Finno-Ugric protoflexid protoflexus protofluoride protoform <span class="searchmatch">protogalactic</span> protogalaxy protogastric protogeneous protogenesis protogenetic protogenic...