ex cathedra has entered the vocabulary of meetings, conferences, etc. and often heads a sheet of announcements or minutes when the chairman or head of the group wishes to make a pronouncement.
Webster's Collegiate- "by virtue of or in the exercise of one's office or position (ex cathedra announcements)

There are a whole passel of these ex whatevers which always should be italicized. A few-
ex libris - from the books of ...
ex mero motu - out of mere impulse
ex animo - from the heart, sincerely
ex nihilo nihil fit - from nothing nothing is produced.
ex ungue leonum -from a part we may judge of the whole (from the claw (we may judge of) the lion.

I knew three out of five; probably average.