circuit
periphery
period
periodic
circumvent
circumstance
circulatory
perigee
circumnavigate
periscope
the condition surrounding an event
a revolviing; a journey around
to sail around
the outer boundary of something
the point in the moon's or a satellite's orbit that is closest to the earth or bod it is orbiting
the interval between certain happenings
and instrument for seeing around things
going in a circuit
happening at regular intervals
to go around or to bypass
