covariant

co- +‎ variant

covariant (not comparable)

1. (category theory, of a functor) Which preservess the order of morphism composition: formally, which associates each morphism ${\displaystyle f:X\to Y}$ to a morphism ${\displaystyle F(f):F(X)\to F(Y)}$.

   Antonym: contravariant

2. (object-oriented programming) Using or relating to covariance.

covariant (plural covariants)

1. (algebra) A bihomogeneous polynomial in x, y, ... and the coefficients of some homogeneous form in x, y, ... that is invariant under some group of linear transformations.
2. (algebra) The variety defined by a covariant.