sea urchin sea unicorn • sea valve · · · Info · Definitions · Characters · · sea urchin · · Text Common · · Latin · · Scripts 10 · · Length 3 · · Syllables Definitions · · · (noun) shallow-water echinoderms having soft bodies enclosed in thin spiny globular shells. Synonyms: sea urchin. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 n latin small letter n U+006E r latin small letter r U+0072 s latin small letter s U+0073 u latin small letter u U+0075