Xiphosura Xiphodontidae • Xiphosuridae · · · Info · Definitions · Characters · · Xiphosura · · Text Latin · · Script 9 · · Length 4 · · Syllables Definitions · · · (noun) horseshoe crabs and extinct forms. Synonyms: order Xiphosura. · · Noun Definition 1 Characters · · X latin capital letter x U+0058 a latin small letter a U+0061 h latin small letter h U+0068 i latin small letter i U+0069 o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073 u latin small letter u U+0075