genesis: A suffix referring to the beginning, development, or production of something. For example, gametogenesis is the development and production of the male and female germ cells (the gametes) required to form a new individual. Osteogenesis is the production of bone. Pathogenesis is the development of a disease, the sequence of events leading up to that disease. The Latin word "genesis" is derived from the Greek "gignesthai" meaning "to be born."