X Priōr

1. former, prior, previous (preceding in time)
2. the first, the original
3. in front
4. (figuratively) better, superior
5. (substantive, Medieval Latin) abbot, prior

This adjective has no positive form; rather, it serves as the comparative (prior) and superlative (prīmus) of the preposition prae. (Compare the preposition post, with comparative posterior and superlative postremus).