(mathematics) The ⊗ operation (the tensor product) when applied to two matrices.

(chemistry) The product of the concentrations of ions, each raised to the power specified by its stoichiometric coefficient in a solution of a salt.

(business) The production of one or a very small number of customized made-to-order goods for a single customer.

(group theory) A generalisation of direct product such that, in one of two equivalent definitions, only one of the subgroups involved is required to be a normal subgroup.

(topology) The topology of the Cartesian product of two or more topological spaces which is generated from a basis whose elements are Cartesian products of open subsets of the original spaces, such that for each such Cartesian product only a finite quantity of such subsets are proper.

(mathematics) For two pointed spaces (i.e. topological spaces with distinguished basepoints) X and Y, the quotient of the product space X × Y under the identifications (x, y₀) ∼ (x₀, y) for all x ∈ X and y ∈ Y; usually denoted X ∧ Y.

(physics) The simultaneous creation of a particle and its antiparticle.

plural of production line

(manufacturing) A set of sequential operations established in a factory whereby materials are put through a refining process or components are assembled to make a finished article.

(chemistry, physics) The product of the individual solubilities of the cation and anion of a salt