Answer: Changing
Step-by-step explanation:
Fluctuate is a rise and fall irregularly in number or amount.
Synonyms:
Vary
Differ
Shift
Change
Alter
Waver
Swing
Oscillate
Alternate
Rise and Fall
Go up and down
See-saw
Yo-yo
Be unstable
Be unsteady
I saw this in the definition of 'fluctuate' on goog.le.
I hope my research helped!