fluctuation
//ˌflʌk.tʃuˈeɪ.ʃən//
Noun
fluctuationSingular
fluctuationsPlural
1
An irregular rising and falling in number or amount; a variation.
There have been significant fluctuations in oil prices this year.
2
A wavelike motion or oscillation.
The fluctuation of the sound waves created a soothing rhythm.