What is "orthogonal complement"

n. (context linear algebra functional analysis English) The set of all vectors which are orthogonal to a given set of vectors.

In the mathematical fields of linear algebra and functional analysis, the orthogonal complement of a subspace W of a vector space V equipped with a bilinear form B is the set W of all vectors in V that are orthogonal to every vector in W. Informally, it is called the perp, short for perpendicular complement. It is a subspace of V.