AC, A.C. or Ac may refer to:
Acetic acid , systematically named ethanoic acid , is a colourless liquid organic compound with the chemical formula CH3COOH (also written as CH3CO2H or C2H4O2).
The Achaemenid Empire (; c. 550–330 BC), also called the First Persian Empire, was an empire based in Western Asia, founded by Cyrus the Great.
An actor (often actress for women; see terminology) is a person who portrays a character in a performance.
The Academy Award for Best Picture is one of the Academy Awards presented annually since the awards debuted in 1929, by the Academy of Motion Picture Arts and Sciences (AMPAS).
An acronym is a word or name formed as an abbreviation from the initial components in a phrase or a word, usually individual words (as in NATO or laser) and sometimes syllables (as in Benelux).
Acupuncture is a form of alternative medicine in which thin needles are inserted into the body. It is a key component of traditional Chinese medicine (TCM).
Acne, also known as acne vulgaris, is a long-term skin disease that occurs when hair follicles are clogged with dead skin cells and oil from the skin.