Physics, Chemistry. 1  a wave function describing the state of a single electron in an atom (atomic orbital) or in a molecule (molecular orbital) 2  the electron in that state.
DEFINITION of 'Yo-Yo'. Slang for a very volatile market. A yo-yo market will have no distinguishing features of either an up or down market, taking on characterstics of both. Security prices in a yo-yo market will swing very high to low over a given period of time, making it difficult for buy and hold investors to profit. Next Up.
So you're overwhelmed with choices and having trouble picking a yo-yo? Don't worry, because here's a buyer's guide to help. The most important thing you need to know is that it's not the yo-yo that makes the player, it's the player that makes the yo-yo. A good yoyo player could take any one of the yo-yos that we sell and do tricks that would delight and amaze any audience. In the end, it's all about practicing, practicing, and more practicing. Yo-yoing is a skill.