contravariant

Meanings

1. Which reverses the order of morphism composition: formally, which associates each morphism f:X→Y to a morphism F(f):F(Y)→F(X).
2. Using or relating to contravariance.
3. Scaling inversely with a change of basis.

1. A bihomogeneous polynomial in dual variables of x, y, ... and the coefficients of some homogeneous form in x, y, ... that is invariant under some group of linear transformations.