Meaning of ex cathedra in English:

ex cathedra

Pronunciation /ˌɛks kəˈθiːdrə/

adverb

  • With the full authority of office (especially that of the Pope, implying infallibility as defined in Roman Catholic doctrine)

    • ‘for an encyclical to be infallible the Pope must speak ex cathedra’
    lawful, legitimate, licit, within the law, legalized, valid

adjective

  • Issued with the full authority of office (especially that of the Pope, implying infallibility as defined in Roman Catholic doctrine)

    ‘ex cathedra statements’
    • ‘an ex cathedra decree’

Origin

Latin, ‘from the (teacher's) chair’, from ex ‘from’ and cathedra ‘seat’ (see cathedral).