conservation

noun

1. (countable, uncountable)The act of preserving, guarding, or protecting; the keeping (of a thing) in a safe or entire state; preservation.
2. (countable, uncountable)Wise use of natural resources.

   ““My father had ideas about conservation long before the United States took it up.[…]You preserve water in times of flood and freshet to be used for power or for irrigation throughout the year. …””

3. (countable, uncountable)The discipline concerned with protection of biodiversity, the environment, and natural resources
4. (countable, uncountable)Genes and associated characteristics of biological organisms that are unchanged by evolution, for example similar or identical nucleic acid sequences or proteins in different species descended from a common ancestor
5. (countable, uncountable)The protection and care of cultural heritage, including artwork and architecture, as well as historical and archaeological artifacts
6. (countable, uncountable)lack of change in a measurable property of an isolated physical system (conservation of energy, mass, momentum, electric charge, subatomic particles, and fundamental symmetries)