terrestrial has 7 distinct synonyms spread across 4 of its 5 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its 2 recorded opposites are amphibious, aquatic.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
of or relating to or characteristic of the planet Earth or its inhabitants
“planetary rumblings and eructations”
operating or living or growing on land
Synonyms, antonyms and the broader and narrower relations for terrestrial come from Princeton University’s WordNet. Full sources and licences.