subspace

[ suhb-speys ]
/ ˈsʌbˌspeɪs /

noun

a smaller space within a main area that has been divided or subdivided: The jewelry shop occupies a subspace in the hotel's lobby.
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