bivariate

From bi- + variate.

bivariate (not comparable)

1. (mathematics) Having or involving exactly two variables.
   • 2016, Grigoriy Blekherman, Daniel Plaumann, Rainer Sinn, Cynthia Vinzant, “Low-Rank Sum-of-Squares Representations on Varieties of Minimal Degree”, in arXiv‎^[1]:

     Our upper bound is the best possible, and it implies the existence of low-rank factorizations of positive semidefinite bivariate matrix polynomials and representations of biforms as sums of few squares.

• two-way

• multivariate
• univariate

• bivariate normal distribution
• bivariately

bivariate (plural bivariates)

1. (mathematics) A polynomial or function with exactly two variables.

• bivariate in Wolfram - Mathworld.