The name of an element of a vector space $E$ in the case when the dual (or conjugate) space (cf. Adjoint space) $E^*$ is considered along with $E$. The elements of $E^*$ are then called covariant vectors (cf. Covariant vector).
Contravariant vector. Encyclopedia of Mathematics. URL: http://www.encyclopediaofmath.org/index.php?title=Contravariant_vector&oldid=33110