sedes impedita /im-pə-dīˈtə or im-pedˈi-ta/ noun

A papal or episcopal see where there is a partial cessation by the incumbent of his episcopal duties

sedes vacans /vāˈkənz, vaˈ or waˈkanz/ (also sede vacante /sēˈdē və-kanˈti, sedˈe va- or wa-kanˈte/) noun

A term of canon law to designate a papal or episcopal see when vacant