A toy consisting of a spheroidal or cylindrical spindle having a circular groove in which string is wound; it is used by holding the string in the fingers and reeling the spindle up and down by movements of the wrist.

(intransitive) To vacillate; to move up and down.

Third-person singular simple present indicative form of yo-yo

plural of yo-yo

simple past tense and past participle of yo-yo

present participle of yo-yo

A series of failed diets that cause a person to lose and gain weight alternately.

plural of yo-yo weight

(astronautics) A method of reducing the rotation rate of a rapidly-spinning spacecraft by unreeling a pair of weights from the spinning spacecraft, greatly increasing the spacecraft's moment of inertia and transferring most of the spacecraft's angular momentum to the weights.

(medicine) The reflux of urine from one moiety of the kidney down the ureter and up into the other moiety, instead of draining into the bladder.