Tethys tethydan • Teton · · · Info · Definitions · Characters · · Tethys · · Text Latin · · Script 6 · · Length Definitions · · · (noun) (Greek mythology) a Titaness and sea goddess; wife of Oceanus. · · Noun Definition 1 (noun) type genus of the family Aplysiidae. Synonyms: Aplysia, genus Aplysia, genus Tethus. · · Noun Definition 2 Characters · · T latin capital letter t U+0054 e latin small letter e U+0065 h latin small letter h U+0068 s latin small letter s U+0073 t latin small letter t U+0074 y latin small letter y U+0079