Bleen

Bleen is an artificial predicate, coined from "green" and "blue" by philosopher Nelson Goodman in one of the seminal works in the philosophy of science, Fact, Fiction, and Forecast. The predicate is used to illustrate what Goodman calls the new problem of induction.

Specifically, "bleen" means "blue before January 1, 2000 and green on or after January 1, 2000". See also grue.

Or bleen may refer to this quote: "The Nobel Prize in mathematics was awarded yesterday to a California professor who has discovered a new number. The number is "bleen", which he says belongs between six and seven." --- George Carlin