Rotations

The act of turning around a centre or an axis.

"The earth's rotation about its axis is responsible for its being slightly oblate rather than a sphere."

A single complete cycle around a centre or an axis.

"Earth's moon completes a rotation every twenty-seven days or so."

A regular variation in a sequence, such as to even-out wear, or people taking turns in a task; a duty roster.

"In rotation, each member of the group would be responsible for the beacon fire."

An operation on a metric space that is a continuous isometry and fixes at least one point.

"The function mapping (x,y) to (−y,x) is a rotation."