sphenoid bone sphenoidal fontanelle • sphenoid fontanel · · · Info · Definitions · Synonyms · Characters · · sphenoid bone · · Text Common · · Latin · · Scripts 13 · · Length 3 · · Syllables Definitions · · · (noun) butterfly-shaped bone at the base of the skull. Synonyms: sphenoid bone, sphenoid, os sphenoidale. · · Noun Definition 1 Synonyms · · · sphenoid · · Synonym 1 os sphenoidale · · Synonym 2 Characters · · space U+0020 b latin small letter b U+0062 d latin small letter d U+0064 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 o latin small letter o U+006F p latin small letter p U+0070 s latin small letter s U+0073