Like some mathematical functions

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
also bi-linear , 1851, from bi- + linear . Related: Bilinearly ; bilinearity .

Wikipedia Word definitions in Wikipedia
Bilinear may refer to: Bilinear sampling (also called "Bilinear filtering"), a method in computer graphics for choosing the color of a texture Bilinear form Bilinear interpolation Bilinear map , a type of mathematical function between vector spaces Bilinear ...

WordNet Word definitions in WordNet
adj. linear with respect to each of two variables or positions

Wiktionary Word definitions in Wiktionary
a. 1 (context mathematics of a function in two variables English) linear (preserving linear combinations) in each variable. 2 (context physics English) Relating to or consisting of two linear functions. n. (context maths English) A bilinear function

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Bilinear \Bi*lin"e*ar\, a. (Math.) Of, pertaining to, or included by, two lines; as, bilinear co["o]rdinates.