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.
Yoshi (also known as Green Yoshi) is a Japanese dinosaur-like creature who appears in the Mario series and is Mario's sidekick, as well as the tritagonist in many games. His debut was in Super Mario World. He later had his own series with several platform and puzzle games, including Super Mario World 2: Yoshi's Island.