terrestrial planet terrestrialness • terrestrial time · · · Info · Definitions · Characters · · terrestrial planet · · Text Common · · Latin · · Scripts 18 · · Length 5 · · Syllables Definitions · · · (noun) a planet having a compact rocky surface like the Earth's; the four innermost planets in the solar system. Synonyms: terrestrial planet. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C n latin small letter n U+006E p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074