portal2 Syllabification: (por·tal)Pronunciation: /ˈpôrtl/Definition of portal adjective [attributive] Anatomy of or relating to an opening in an organ through which major blood vessels pass, especially the transverse fissure of the liver. Origin: mid 19th century: from modern Latin portalis, from Latin porta 'gate'portal in other Oxford dictionaries Definition of portal in the British & World English dictionary