- noun all the changes an organism goes through between a specific stage in its development and the same stage in the next generation
- noun a concept used for charting the different stages in the life of people, animals, or products
- A term often used to describe the period of time that a building can be expected to actively and adequately serve its intended function.
- The interval during which a component, device, piece of equipment, system, material, or the like, is useful. Once this period elapses, it becomes increasing less advisable to invest additional resources in maintenance, repairs, replacements, and improvements.