The continuous development of cells in tissue formation; cell formation.
- The process by which an organism produces others of its kind; breeding, propagation, procreation, reproduction.
- The act of increasing or rising; augmentation, amplification, enlargement, escalation, aggrandizement.
- The result of building up; buildup, accretion.
- The spread of biochemical, nuclear and other weapons of mass destruction to countries not originally involved in developing them.