noun A pipe or chamber branching into several openings. (the pipeline manifold) A collection of points forming a certain kind of set, such as those of a topologically closed surface or an analog of this in three or more dimensions. (Topology is the mathematical discipline concerned with surfaces or manifolds in higher dimensions.) (in Kantian philosophy) the sum of the particulars furnished by sense before they have been unified by the synthesis of the understanding.
adjective Many and various. (the implications of this decision were manifold)