subspace
n.a smaller space inside a larger space where the rules of the bigger space still work. In math, it is a set of points that follows the same rules as the whole space.
n.a subset of a vector space that is itself a vector space under the same operations. It must contain the zero vector and be closed under addition and scalar multiplication.
“The set of all solutions to this equation forms a subspace.”
“In linear algebra, we often look for a subspace that contains only the vectors that satisfy a specific condition.”
“The intersection of two subspaces is itself a subspace, provided that the original subspaces are defined over the same field and share the same dimensionality.”
From sub- + space.
From sub (“submissive”) + space (“state of mind”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.