RHOMBENCEPHALON /ɹɒmbɛnˈkɛfəlɒn/ Scrabble 29 Words With Friends 34 Definition noun the posterior portion of the brain including cerebellum and brainstem. — synonyms: hindbrain See all 1134 words you can make from RHOMBENCEPHALON → 15-letter words Words starting with R Words ending with N ← Unscramble different letters