Arcology is a combination of the words Architecture and Ecology and was coined and put in practice by the Italian Architect Paolo Soleri.
An arcology is distinguished from a merely large building in that it is supposed to sustainably supply all or most of the resources for a comfortable life: power, climate control, food production, air and water purification, sewage treatment etc.. It is supposed to supply these items for a large population and reduce human impact on dwindling natural resources. An arcology would need no connections to municipal or urban infrastructure in order to operate. Soleri describes ways of compacting city structures in three dimensions to combat two dimensional urban sprawl and economize on transportation and other energy uses.
Soleri's plans are not just "human beehives". Like Wright, Soleri proposed important changes in transportation, agriculture and commerce. Soleri explored reductions in resource consumption and duplication, land reclamation and proposed to eliminate most private transportation. He favored greater use of shared social resources like public libraries.
Soleri's work on arcology started in 1970, the Arcosanti project (above) is a community planned for 5000 people. Located near Cordes Junction, 70 miles north of Phoenix, Arcosanti is a prototype of a desert arcology, the first attempt to provide a new way of social aggregation and still today is a work in progress. Many cities are currently planning arcologies even if the term is sometimes incorrectly extended to a series of ecological or energy efficient buildings or neighborhoods rather than to a single mega structure: an example is the now defunct Dongtan Project pictured below: