B2 to change suddenly or completely, especially from one thing to another, or to exchange by replacing one person or thing with another: She started studying English at college, but switched to Business Studies in her second year. In 1971, Britain switched over (= changed completely) to a decimal currency. After the bank robbery, the gang switched cars (= left one car and got into another).ChangingAdapting and modifying Adapting and attuning to somethingChanging frequently