adjective Mathematics.
- of, relating to, or having reference to two lines: bilinear coordinates.
- of the first degree in each of two variables, as an equation.
adjective
- of or referring to two lines
- of or relating to a function of two variables that is linear in each independently, as f(x, y) = xy
also bi-linear, 1851, from bi- + linear. Related: Bilinearly; bilinearity.