"Moonshine" denotes a concept used in advanced mathematics.

The term "moonshine" or "monstrous moonshine" is found in quantum algebra. In a 2001 paper, T. Gannon defines it as follows:

At minimum, Moonshine should be regarded as a certain collection of related examples where algebraic structures have been associated automorphic functions or forms. (p. 7)

There are a number of conflicting reasons given why this association received the name of "Moonshine." One explains it as an expression of incredulity uttered by one researcher on being told about part of the concept. Another traces it to a bottle of whiskey offered as a prize by another mathematician to anyone who could answer a question related to it.