The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
per-1
DEFINITION:
To produce, procure. Oldest form *per2-; possibly related to per-2. See also per-5II. Derivatives include parade, parry, emperor, parachute, sever, and parent. I. Zero-grade form *p- (becoming *par- in Latin). a. Suffixed form *par--.parade, pare, parlay, parry, parure; apparatus, apparel, comprador, disparate, emperor, imperative, imperator, imperial, parachute, parasol, prepare, rampart, repair1, separate, sever, several, from Latin parre, to try to get, prepare, equip; b. suffixed form *par-yo-.para, parity2, parous, parturient, postpartum, repertory, viper, from Latin parere,parre, to get, beget, give birth; c. parallel suffixed (participial) form *par-ent-.parent, from Latin parns, parent; d. suffixed form *par-o-, producing: (i)juniper, from Latin iniperus, juniper, perhaps from compound *yoini-paros, producing juniper berries (*yoini-, juniper berry); (ii) compound *pau-paros (see pau-); (iii) Italic compound *wwo-paros (see gwei-); e. suffixed form *par-ik-.Parcae, from Latin Parcae, the Fates (who assign one's destiny). II. Suffixed o-grade form por()-s-.heifer, from Old English hahfore, calf, a compound (with obscure first element) of fearr, calf, from Germanic *farz-. (Pokorny 2. D. per 818.)