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Webster 1913 Edition
Cathedra
‖
Cath′e-dra
,Noun.
[L., fr. Gr. [GREEK] seat. See
Chair
.] The official chair or throne of a bishop, or of any person in high authority.
Ex cathedra
[L., from the chair]
, in the exercise of one’s office; with authority.
The Vatican Council declares that the Pope, is infallible “when he speaks
ex cathedra
.” Addis & Arnold's Cath. Dict.