periphery (n.) Look up periphery at Dictionary.com
late 14c., "atmosphere around the earth," from Old French periferie (Modern French périphérie), from Medieval Latin periferia, from Late Latin peripheria, from Greek peripheria "circumference, outer surface, line round a circular body," literally "a carrying around," from peripheres "rounded, moving round, revolving," peripherein "carry or move round," from peri- "round about" (see peri-) + pherein "to carry" (see infer). Meaning "outside boundary of a surface" attested in English from 1570s; general sense of "boundary" is from 1660s.