prefix
Etymology: Latin, from Greek, from peri; akin to Greek peran to pass through — more at fare
1. : all around : about : round
Peri arctic
peri center
peri cyclone
peri scope
2. : near
peri helion
3.
a. : enclosing or surrounding
peri neurium
peri proct
peri sinuous
b. : tissue surrounding (a specified part) — in terms in -itis
peri arthritis
4. usually italic : having substituents in or relating to positions 1 and 8 in two fused 6-membered rings (as in naphthalene)