fluctuation
n.a change that moves up and down over time, like the price of a product or the weather. It describes something that is not steady or constant.
n.a change that varies between different levels or states over a period of time. Often refers to economic or environmental variables that experience periodic rises and falls.
“The price of gas has seen a lot of fluctuation this year.”
“Market fluctuation is a normal part of investing, but sudden drops can cause many people to lose their confidence.”
“Economists are closely monitoring the fluctuation in consumer spending to determine whether the current recovery is sustainable or merely a temporary rebound.”
“Now combine this with the natural fluctuations of women's hormones, which already put our brain's temperature regulation systems "out of kilter", according to Dr Arif.”
“The problem, she said, was exacerbated by inflation and currency fluctuations.”
Common in science writing
Borrowed from Latin fluctuatiōnem, accusative singular of fluctuatiō, from fluctuō, from fluctus. Morphologically fluctuate + -ion.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.