axis - a line around which something turns

rotate - to spin around an axis  The Earth makes one complete rotation every day (24 hours).

revolve - to travel in a circle around something else  The Earth makes one complete revolution around the sun every year (365 days).

planet - large round object in space that circles (orbits) around the sun (or another star)  The word actually means "wanderer" because planets change their positions  from night to night.