1 [mathematics] A number that indicates the importance of a variable for a particular calculation. The larger the weight assigned to the variable, the more that variable will influence the outcome of the operation.
2 [ESRI software] A property of a network element typically used to describe the element or to assign a cost for traversing the element. For example, this value may represent the phase or the length of a primary conductor in an electrical distribution system. Weights are calculated based on an attribute of each network feature.