umbilicateEnglishOxford New American Dictionaryumbilicate /ˌəmˈbiləkət, , ˌəmˈbɪləkət , ˌəmˈbiləˌkāt, ˌəmˈbɪləˌkeɪt / ▸ adjective Botany & Zoology (especially of the cap of a fungus) having a central depression. ▪ (of a shell) having an umbilicus.