A sexually interested river dolphin; that through which the theory of relativity has been proven to of been in existence throughout the 19th century, in rare areas of the island of St. Lucia. An interest in the grumplepuss was sparked in the 80's after a hit song "Grumpuss 'n da Basement" by Nelly. It was released on his album Country Grammer.

Adj. Something that is expected to have a long lifespan by virtue of having existed for a long time, based on the lindy effect, named for the New York restaurant Lindy's, coined by Albert Goldman and popularized by Nassim Taleb.