PARASANG n.
A Persian measure of length, which, according to Herodotus and Xenophon, was thirty stadia, or somewhat more than three and a half miles. The measure varied in different times and places, and, as now used, is estimated at from three and a half to four English miles.
PERI- n.
signify around, by, near, over, beyond, or to give an intensive sense; as, perimeter, the measure around; perigee, point near the earth; periergy, work beyond what is needed; perispherical, quite spherical.