Definitions for "Quantum number"
a number describing a property of an electron in an atom.
A number that labels a state, it denotes the number of quanta of a particular type that the state contains. Electric charge given as an integer multiple of the electron's charge is an example of a quantum number.
Indices that label quantized energy states. Quantum numbers are used to describe the state of a confined electron, e. g. an electron in an atom.