brachiosaurus Get Printable Handwriting (bra-chi-o-saur-us) 5 syllables Learn It! Spelling Test Definition noun. any of a genus of huge Jurassic sauropods having longer forelegs than hind legs and nostrils high on the forehead Example Sentence The brachiosaurus is the largest known land animal. Synonyms sauropod dinosaur; dinosaur; huge dinosaur Antonyms kitty cat Share with your friends: