An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) Logic: Relating to or involving deductive reasoning from a general principle to the expected facts or effects (dictionary.com).
2) Logic: Known to be true independently of or in advance of experience of the subject matter; requiring no evidence for its validation or support (dictionary.com). → a posteriori.

L., literally "from what comes first," from priori, ablative of prior "former, previous, first," → per-.

Partom "the first," Dehxodâ: fardom; Mid.Pers. fradom, fratom, pratom; O.Pers. fratama-; Av. fratəma- (Skt. prathama- "earliest, initial, first") superlative of fra- "before, forward, forth," cognate with Gk. and L. → pro-.

1) Preceding in time or in order; earlier or former; previous.
2) Preceding in importance or privilege.

O.E., from M.L. prior "former, previous, first, superior," comparative of O.L. pri "before," from PIE *prai-, *prei-, from root *per- "forward, through," → pro-.

Parin, from pra-, fra- "before, forward, forth," cognate with Gk. and L. → pro-.

The condition or quality of being earlier in time or occurrence, or being regarded as more important.

→ prior; → -ity.