variation

noun

1. 1.The act of varying; a partial change in the form, position, state, or qualities of a thing.
2. 2.A related but distinct thing.
3. 3.The angular difference at the vessel between the direction of true north and magnetic north.
4. 4.A line of play that differs from the original.
5. 5.A technique where material is repeated with alterations to the melody, harmony, rhythm, timbre, texture, counterpoint or orchestration; but with some invariant characteristic, e.g. a ground bass.