An Oscillation

1. the act of oscillating or the state of being oscillated
2. a regular periodic fluctuation in value about some mean https://en.wikipedia.org/wiki/Oscillation
3. a single such cycle
4. (mathematics) (of a function) defined for each point {\displaystyle x} in the domain of the function by {\displaystyle \inf \left{\mathrm {diam} (f(U))\mid U\mathrm { is a neighborhood of } x\right}}, and describes the difference (possibly ∞) between the limit superior and limit inferior of the function near that point. Oscillation (mathematics) - Wikipedia