Noun

The act of preserving, guarding, or protecting; the keeping (of a thing) in a safe or entire state; preservation.

Wise use of natural resources.

* {{quote-book, year=1913, author=

, title=Lord Stranleigh Abroad , chapter=4 citation , passage=“My father had ideas about conservation long before the United States took it up.

(biology) The discipline concerned with protection of biodiversity, the environment, and natural resources

(biology) 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

(culture) The protection and care of cultural heritage, including artwork and architecture, as well as historical and archaeological artifacts

(physics) lack of change in a measurable property of an isolated physical system (conservation of energy, mass, momentum, electric charge, subatomic particles, and fundamental symmetries)

Noun

(en noun)

The action of making or becoming extinct; annihilation.

*{{quote-magazine, date=2012-01

, author=Donald Worster , title=A Drier and Hotter Future , volume=100, issue=1, page=70 , magazine= citation , passage=Phoenix and Lubbock are both caught in severe drought, and it is going to get much worse. We may see many such [dust] storms in the decades ahead, along with species extinctions , radical disturbance of ecosystems, and intensified social conflict over land and water. Welcome to the Anthropocene, the epoch when humans have become a major geological and climatic force.}}

(astronomy) The absorption or scattering of electromagnetic radiation emitted by astronomical objects by intervening dust and gas before it reaches the observer.