prior-

(Latin: former; first; superior)

Directly related to the prim- family unit of words.

priory (s) (noun), priories (pl)
A religious residence in a monastery governed by a prior or a convent governed by a prioress.
subprior (s) (noun), subpriors (pl)
The vicegerent of a prior; a claustral officer who assists the prior.
top priority, top-priority (s) (noun); top priorities, top-priorities (pl)
Item of highest importance. A redundant statement?