periphery

Concise Oxford English Dictionary © 2008 Oxford University Press:
periphery /pəˈrɪf(ə)ri/

▶noun (pl. peripheries)

• 1 the outer limits or edge of an area or object.

• 2 a marginal or secondary position, part, or aspect.

– origin C16: via late L. from Gk periphereia ‘circumference’.