noun: Used other than figuratively or idiomatically: see full, circle.
noun: (geometry) An arc of 360 degrees.
noun: A full turn back to the original direction or orientation.
noun: By extension, of a discussion, a point arrived at which is the same point at which it began; the point at which effort has resulted in no progress.
adverb: Through a rotation or revolution that ends at the starting point.
adverb: (idiomatic) Through a cycle of transition, returning to where one started after gaining experience or exploring other things.