rotation

1. The act of turning around a centre or an axis. (uncountable) · The earth's rotation about its axis is responsible for its being slightly oblate rather than a sphere.
2. A single complete cycle around a centre or an axis. (countable, uncountable) · Earth's moon completes a rotation every twenty-seven days or so.
3. A regular variation in a sequence, such as to even out wear, or people taking turns in a task; a duty roster. (countable, uncountable) · Applying crop rotation to a field avoids depleting soil nutrients the way repeated use of a single crop might do.· In rotation, each member of the group would be responsible for the beacon fire.
4. Тhe movement of investments between different sectors of an economy, or styles of investing, based on anticipated changes in the economic or market cycle. (countable, uncountable)
5. An operation on a metric space that is a continuous isometry and fixes at least one point. (countable, uncountable) · The function mapping (x,y) to (−y,x) is a rotation.
6. The set of starting pitchers of a team. (countable, uncountable)
7. The step during takeoff when the pilot commands the vehicle to lift the nose wheel off the ground during the takeoff roll. (see also: V2) (countable, uncountable)
8. Repeated play of songs on a radio station, advertisements on a television channel, etc. (countable, uncountable) · The new single enjoyed heavy rotation on MTV.

Plural rotations