evolution

UK: /ˌiːvəˈluːʃ^ən/

US: /ˌɛvəˈluʃən; esp. Brit. ˌivə-/

US: (ev′ə lo̅o̅′shən or, esp. Brit., ē′və-)

WordReference Random House Learner's Dictionary of American English © 2026

ev•o•lu•tion /ˌɛvəˈluʃən; esp. Brit. ˌivə-/   n. [uncountable]

1. any process of formation or growth;
   development:
   the evolution of the drama.
2. Biology Biol.
   • change in a population of living things by such processes as mutation and natural selection.
   • the theory that all existing organisms developed from earlier forms by natural selection.

ev•o•lu•tion•ar•y, adj. 

WordReference Random House Unabridged Dictionary of American English © 2026

ev•o•lu•tion  (ev′ə lo̅o̅′shən or, esp. Brit., ē′və-), n. 

1. any process of formation or growth;
   development:
   the evolution of a language; the evolution of the airplane.
2. a product of such development;
   something evolved:
   The exploration of space is the evolution of decades of research.
3. Biology change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift.
4. Sociology a process of gradual, peaceful, progressive change or development, as in social or economic structure or institutions.
5. a motion incomplete in itself, but combining with coordinated motions to produce a single action, as in a machine.
6. a pattern formed by or as if by a series of movements:
   the evolutions of a figure skater.
7. Thermodynamics an evolving or giving off of gas, heat, etc.
8. Mathematics the extraction of a root from a quantity. Cf. involution (def. 8).
9. Military a movement or one of a series of movements of troops, ships, etc., as for disposition in order of battle or in line on parade.
10. Military any similar movement, esp. in close order drill.

• Latin ēvolūtiōn- (stem of ēvolūtiō) an unrolling, opening, equivalent. to ēvolūt(us) (see evolute) + -iōn- -ion
• 1615–25

ev′o•lu′tion•al, adj. 
ev′o•lu′tion•al•ly, adv. 
Synonyms

• 1. unfolding, change, progression, metamorphosis.

Antonyms

• 1. stasis, inactivity, changelessness.

Collins Concise English Dictionary © HarperCollins Publishers::

evolution / ˌiːvəˈluːʃən/ noun

1. a gradual change in the characteristics of a population of animals or plants over successive generations: accounts for the origin of existing species from ancestors unlike them
   See also natural selection
2. a gradual development, esp to a more complex form: the evolution of modern art
3. the act of throwing off, as heat, gas, vapour, etc
4. a pattern formed by a series of movements or something similar
5. an algebraic operation in which the root of a number, expression, etc, is extracted
   Compare involution6
6. an exercise carried out in accordance with a set procedure or plan

Etymology: 17th Century: from Latin ēvolūtiō an unrolling, from ēvolvere to evolve

ˌevoˈlutionary, ˌevoˈlutional adjective