fluc ‧ tu ‧ ate AC /ˈflʌktʃueɪt/ BrE AmE verb [intransitive]
[ Word Family: verb : ↑ fluctuate ; noun : ↑ fluctuation ]
[ Date: 1600-1700 ; Language: Latin ; Origin: fluctuare , from fluere ; ⇨ ↑ fluent ]
if a price or amount fluctuates, it keeps changing and becoming higher and lower SYN vary
fluctuate between
Prices were volatile, fluctuating between $20 and $40.
fluctuate around
The number of children in the school fluctuates around 100.
Insect populations fluctuate wildly from year to year.