- Abbreviation of exclusive NOR. A logical operation which is true if all of its elements are the same. For example, if all of its multiple inputs have a value of 0, then the output is 1. And, if all of its inputs have a value of 1, then the output is 1. Any other combination yields an output of 0. For such functions, a 1 is considered as a true, or high, value, and 0 is a false, or low, value. Also called XNOR operation.