Bucephalus Syllabification: (Bu·ceph·a·lus)Pronunciation: /byo͞oˈsefələs/Definition of Bucephalus the favorite horse of Alexander the Great, who tamed the horse as a boy and took it with him on his campaigns until its death, after a battle, in 326 bc. Bucephalus in other Oxford dictionaries Definition of Bucephalus in the British & World English dictionary