rhombencephalon rhomb • rhombenporphyr · · · Info · Definitions · Synonyms · Characters · · rhombencephalon · · Text Latin · · Script 15 · · Length Definitions · · · (noun) the posterior portion of the brain including cerebellum and brainstem. Synonyms: hindbrain. · · Noun Definition 1 Synonyms · · · hindbrain · · Synonym 1 Characters · · a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 e latin small letter e U+0065 h latin small letter h U+0068 l latin small letter l U+006C m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072