Definition Of yo-yo
a toy consisting of a pair of joined discs with a deep groove between them in which string is attached and wound, which can be spun alternately downward and upward by its weight and momentum as the string unwinds and rewinds.
It is something like the toy we call a yo-yo : you play with it and make it spin, but there is always a string attached.
move up and down; fluctuate.
popularity polls yo-yo up and down with the flow of events
Example Of yo-yo
A seasoned Weight Watchers member, Fiona already enjoyed a reasonably good diet but was still plagued by the all too familiar yo-yo syndrome.
A self-identified yo-yo fanatic, he's one of a hundred official Coca-Cola yo-yo collectors in this country.
After 20 years of yo-yo light dieting, Butler joined Overeater's Anonymous and started to take control.
As for food, yo-yo diets, involving periods of near starvation, damage valuable muscle and are positively unhealthy.
Fad diets only add to the confusion and contribute to the yo-yo syndrome so many of us experience.