Is it ensure, insure, or assure?
1777, from Persian pari, from Avestan pairika. Race of superhuman female beings originally represented as malevolent, later as angelic genii (cf. sense evolution of English fairy, to which it is not related).
word-forming element meaning "around, about, enclosing," from Greek peri (prep.) "around, about, beyond," cognate with Sanskrit pari "around, about, through," Latin per, from PIE *per- (1) "forward, through" (see per).
Around; about; enclosing: perimysium.
A prefix that means: "around" (as in pericardium,) or "near" (as in perihelion).