variation

noun10

1. •
   The act of varying; a partial change in the form, position, state, or qualities of a thing.
2. •
   The modification of a hereditary trait.
3. •
   Deviation from the mean orbit of a heavenly body.
4. •
   A related but distinct thing.

   • When the process didn't work, we tried a variation.
   • All of his soups are variations on a single recipe.
5. •
   A line of play that differs from the original.
6. •
   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.
7. •
   The situation where two or more linguistic forms appear in the same environment without a change in meaning, the choice of form being determined by factors of dialect, sociolect, register or simply the speaker's preference.
8. •
   The angular difference at the vessel between the direction of true north and magnetic north.
9. •
   An infinitesimal perturbation applied to a function, typically denoted δf, used to probe how a functional changes.
10. •
    The corresponding first-order change in a functional induced by such a perturbation, typically denoted δJ[f] and called the first variation.