WordNet (r) 3.0 (2006):

Cartesian product
    n 1: the set of elements common to two or more sets; "the set of
         red hats is the intersection of the set of hats and the set
         of red things" [syn: intersection, product, Cartesian
         product]

The Free On-line Dictionary of Computing (30 December 2018):

Cartesian product

    (After Renee Descartes, French philosper and
   mathematician) The Cartesian product of two sets A and B is
   the set

   	A x B = (a, b) | a in A, b in B.

   I.e. the product set contains all possible combinations of one
   element from each set.  The idea can be extended to products
   of any number of sets.

   If we consider the elements in sets A and B as points along
   perpendicular axes in a two-dimensional space then the
   elements of the product are the "Cartesian coordinates" of
   points in that space.

   See also tuple.

   (1995-03-01)