1. any of a range of statistical techniques used to situate an item that could belong to any of two or more variables in the correct set, with minimal probability of error.

2. in discriminant analysis more specifically, a linear combination of predictor variables that is used to categorize items into distinct groups. The first discriminant function denotes the linear combination that best distinguishes among the discrete groups, the second discriminant function is the linear combination that is the next best in distinguishing among the groups, and so forth.