Prior (?), a. [L. prior former, previous, better, superior; compar. corresponding to primus first, and pro for. See Former, and cf. Prime, a., and Pre-, Pro-.] 1. Preceding in the order of time; former; antecedent; anterior; previous; as, a prior discovery; prior obligation; -- used elliptically in cases like the following: he lived alone [in the time] prior to his marriage.
[1913 Webster]

2. First, precedent, or superior in the order of cognition, reason or generality, origin, development, rank, etc.
[Webster 1913 Suppl.]

Prior, n. a prior conviction; -- said of an accused criminal. [informal]
[PJC]