Noun
bidual (plural biduals)
(mathematics) The dual of a dual.
A Banach space can be canonically identified with a subspace of its bidual, which is the dual of its dual space. Source: Internet
Being the dual of a normed space, the bidual X ′′ is complete, therefore, every reflexive normed space is a Banach space. Source: Internet
Furthermore, this space J is isometrically isomorphic to its bidual. Source: Internet