1. a smaller space within a main area that has been divided or subdivided: The jewelry shop occupies a subspace in the hotel's lobby.
  2. Mathematics.
    1. a subset of a given space.
    2. Also called linear manifold.a subset of a vector space which is itself a vector space.
    3. a subset of a topological space, having the relative topology.

Origin of subspace

First recorded in 1925–30; sub- + space Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018