Noun
pseudovector (plural pseudovectors)
(mathematics, physics) A quantity that transforms like a vector under a proper rotation but gains an additional change of sign under an improper rotation
Angular momentum is a vector quantity (more precisely, a pseudovector ) that represents the product of a body's rotational inertia and rotational velocity about a particular axis. Source: Internet
The cross product can be written as : For arbitrary choices of spatial orientation (that is, allowing for left-handed as well as right-handed coordinate systems) the cross product of two vectors is a pseudovector instead of a vector (see below). Source: Internet