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

(uncountable) The process of developing; growth, directed change.

* {{quote-magazine, date=2013-07-19, author= Ian Sample

, volume=189, issue=6, page=34, magazine=(The Guardian Weekly) , title= Irregular bedtimes may affect children's brains , passage=Irregular bedtimes may disrupt healthy brain development in young children, according to a study of intelligence and sleeping habits.  ¶ Going to bed at a different time each night affected girls more than boys, but both fared worse on mental tasks than children who had a set bedtime, researchers found.}}

(uncountable, biology) The process by which a mature multicellular organism or part of an organism is produced by the addition of new cells.

*

Of more significance in the nature of branch development ; in the Jubulaceae, as in the Porellaceae, branches are acroscopic and normally replace a ventral leaf lobe.

(countable) Something which has developed.

(real estate, countable) A project consisting of one or more commercial or residential buildings, real estate development.

(real estate, uncountable) The building of a real estate development.

(uncountable) The application of new ideas to practical problems (''cf. research).

(chess, uncountable) The active placement of the pieces, or the process of achieving it.

(music) The second section of a piece of music in sonata form.