Oxford Dictionary English alternating current nounnoun BrE BrE//ˌɔːltəneɪtɪŋ ˈkʌrənt// ; NAmE NAmE//ˌɔːltərneɪtɪŋ ˈkɜːrənt// [uncountable, countable] (abbreviation AC) Add to my wordlistjump to other results an electric current that changes its direction at regular intervals many times a second compare direct currentSee alternating current in the Oxford Advanced American DictionaryCheck pronunciation: alternating current oxfordlearnersdictionaries.com