smile
n.— «A reference to the common shape of a graph of at- or out-of-the-money put and call implied volatilities for options with a common expiration date. The name comes from the fact that the furthest out of the money options generally have the highest implied volatilities, causing the ends of the graph to turn up. » —by Gary L. Gastineau, Mark P. Kritzman Dictionary of Financial Risk Management , 1999. (source: Double-Tongued Dictionary)
Further reading
There are eight major planets, but more than a million minor ones, including asteroids. If you discover one, you get the honor of naming it. The Dictionary of Minor Planet Names includes minor planets named for rock bands, jazz musicians, poets, and...
One of the celestial bodies listed in The Dictionary of Minor Planet Names(Amazon) is called Sumaura. It’s the name of the oldest private elementary school in Kobe, Japan, and was suggested by the discoverer’s son. This is part of a...