Prior
early 18th century: from Latin, literally ‘former, elder’, related to prae ‘before’.
wiktionary
From Latin prior, comparative of Old Latin *pri(“before”), from Proto-Indo-European *per-(“beyond”), *pro(“before”). Parallel to English former, as comparative form from same Proto-Indo-European root, whence also fore (thence before).
From Middle English priour, prior, from Old English prior, Old French prior, and their etymon Latin prior.
etymonline
prior (adj.)
"earlier; preceding, as in order of time," 1714, from Latin prior "former, previous, first;" figuratively "superior, better;" as a noun "forefather; superior rank;" comparative of Old Latin pri "before" (from PIE *prai-, *prei-, from root *per- (1) "forward," hence "in front of, before, first"). Also used adverbially (with to), by 1706.
prior (n.)
"superior officer of a religious house or order," Middle English priour, from late Old English, and directly from Medieval Latin prior "superior officer," noun use of Latin adjective meaning "former, superior" (see prior (adj.)). As short for prior arrest, by 1990, American English.
