An Etymological Dictionary of Astronomy and Astrophysics

L. prefix meaning “around, round about.”

Etymology (EN): From L. circum “around,” accusative of circus “circle, ring,” from Gk. kirkos, krikos “ring,” PIE *sker-, *ker- “to turn, bend.”

Etymology (PE): Pirâ- “around, about,” variants par-, fer-, pâl- (as in ferdows, pardis, pâliz, from Av. pairidaeza- “enclosure, park”); Mid.Pers. pêrâ;
O.Pers. pariy “around, about;” Av. pairi “around, over;” cf. Skt. pari;
Indo-Iranian *pari- “around;” Gk. peri “around, about, beyond;” L. per “through;” PIE base *per- “through, across, beyond.” The word paradize, with various forms in European languages,
is a loan from Av. pairidaeza- “enclosure, park” (other Av. examples: pairifrâsa- “asking round about,” pairivâra- “circumvallation”).