group action - action taken by a group of people

compounding, combining, combination - the act of combining things to form a new whole

centralisation, centralization - the act of consolidating power under a central control

incorporation - consolidating two or more things; union in (or into) one body

amalgamation, merger, uniting - the combination of two or more commercial companies

vertical combination, vertical integration - absorption into a single firm of several firms involved in all aspects of a product's manufacture from raw materials to distribution

horizontal combination, horizontal integration - absorption into a single firm of several firms involved in the same level of production and sharing resources at that level

mathematical operation, mathematical process, operation - (mathematics) calculation by mathematical methods; "the problems at the end of the chapter demonstrated the mathematical processes involved in the derivation"; "they were learning the basic operations of arithmetic"