Related to or located in the peripheral nervous system.
Unimportant.
Beside the point.
On the periphery or boundary.
Auxiliary.
Peripheral vision.
A peripheral device.
A cord connecting an astronaut to a spacecraft, or a craft to ground control prior to launch, etc.
Of, or relating to, the navel (umbilicus) or the umbilical cord.
Such that the curvatures of normal sections are all equal to each other.