Meaning of “evolution” - Learner’s Dictionary

evolution

noun [ U ] uk us /ˌiːvəˈluːʃən/
LIFE

B2 the way in which living things gradually change and develop over millions of years:

Darwin's theory of evolution
GRADUAL CHANGE

B2 a gradual process of change and development:

the evolution of language
evolutionary adjective

(Definition of “evolution” from the Cambridge Learner’s Dictionary © Cambridge University Press)