A Quick and Simple Dictionary

oscillation

1. Noun.  the act of oscillating or the state of being oscillated.
2. Noun.  a regular periodic fluctuation in value about some mean.
3. Noun.  a single such cycle.
4. Noun.  (mathematics) (context, of a function) defined for each point $x$ in the domain of the function by $infleft\{mathrm\{diam\}(f(U))mid\; Umathrm\{\; is\; a\; neighborhood\; of\; \}x\; ight\}$, and describes the difference (possibly ∞) between the limit superior and limit inferior of the function near that point.