A toy consisting of a spool that is reeled up and down on a string by motions of the hand WordNet 3.0 & Open English WordNet

A yo-yo is a toy consisting of an axle connected to two disks, and a string looped around the axle, similar to a spool. Wikipedia

Toy. Wikipedia Disambiguation

Toy Wikidata

A toy consisting of two weighted discs as a weight, connected with an axle, around which string is wound. There is a loop at the end of the string; the toy is played by putting the loop around a finger, grasping the weight, and throwing it in a smooth motion. Some tricks may be performed before letting the weight return to the hand. OmegaWiki

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. Wiktionary