出典:Wiktionary
From Proto-Indo-European *prokʷe, from *pro- + *-kʷe (equivalent to Latin pro + -que). The expected form would accordingly be *proque. The second -p- is probably due to assimilation. Compare the reverse development in quinque, coquo, which was hindered here by the initial cluster pr-. A less likely explanation is borrowing from Oscan, where - (-pe) is the regular reflex.
prope (comparative propius, superlative proximē または proxumus または proximus)
prope (+ accusative)