yo-yo

noun

Pronunciation: /ˈjəʊ.jəʊ/ / /ˈjoʊ.joʊ/ / /ˈjəʉ.jəʉ/

Etymology: Genericized trademark. Most likely from Ilocano yóyo, or another Philippine cognate.

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.
“I bought a yo-yo from the toy store yesterday.”
A volatile market that moves up and down.
Someone who vacillates.
A dogfighting maneuver involving the attacker temporarily exchanging altitude for airspeed, or vice versa, in order to rapidly catch up with the defender or to prevent an overshoot.
A cloth rosette formed by gathering the outside edge of a circle of fabric in toward the centre using a running stitch.
A foolish, annoying or incompetent person.
“It is hard to watch the management for very long and not conclude that the place is run by a bunch of yo-yos.”
“Now look at them yo-yos, that's the way you do it”

Etymology: Genericized trademark. Most likely from Ilocano yóyo, or another Philippine cognate.

To vacillate; to move up and down.
“The yo-yoing stockmarket whizzed back up by around a quarter and then started to fall again.”