1. ex cathedra - Adverb
2. ex cathedra - Phrase
with the full authority of the office
Source: WordNetthe pope must speak ex cathedra for an encyclical to be infallible Source: Internet
Lee states, "When parsimony ceases to be a guideline and is instead elevated to an ex cathedra pronouncement, parsimony analysis ceases to be science." Source: Internet
That argument disaggregates ex cathedra teachings from infallible teachings, underscoring (correctly) that a teaching may be infallible without being ex cathedra. Source: Internet
The final vote, with a choice only between placet and non placet, was taken on 18 July 1870, with 433 votes in favour and only 2 against defining as a dogma the infallibility of the pope when speaking ex cathedra. Source: Internet