Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “AC”

AC

noun uk   /ˌeɪˈsiː/ us  

AC noun (ELECTRICITY)

[U] abbreviation for alternating current: electrical current that regularly changes the direction in which it flows
Compare
Electricity and electronics

AC noun (AIR)

[C or U] US abbreviation for air conditioner or air conditioningVents and ventilation
(Definition of AC noun from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of AC?
Add Cambridge dictionaries to your browser to your website

Definitions of “AC” in other dictionaries

Word of the Day

flair

natural ability to do something well

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More