AC

Look up AC, ac, a/c, or ℀ in Wiktionary, the free dictionary.

AC, A.C. or Ac may refer to:

Air conditioning (often referred to as aircon, AC or A/C), the process of altering the properties of air (primarily temperature and humidity) to more favourable conditions
Alternating current, a type of electrical current where the current repeatedly changes direction
Air Canada, the flag carrier and largest airline of Canada by IATA code

Computing

AC (complexity), a hierarchy of complexity classes found in circuit complexity
Authorization certificate or attribute certificate, a digital permission to use a service or resource
.ac, Internet top-level domain name for Ascension Island
.ac (second-level domain), Internet second-level domain used to denote academic institutions in many countries

AC Comics, a comic book publisher established in 1969
A.C. Newman, solo stage-name for Canadian musician Carl Newman
A.C. Slater, character in the American sitcom Saved by the Bell
"AC radio," Adult contemporary music, a genre description used mainly in radio broadcasting
After Colony, an alternate timeline in the Gundam metaseries for the universe of Gundam Wing
American Capitalist, the third studio album from American rock band 5FDP
Anal Cunt, an American musical group
Armor Class, a combat-related parameter in the Dungeons & Dragons role playing game system
AC, the name of the ultimate computer at the end of time in Isaac Asimov's The Last Question

Ace Combat, a series of combat flight simulator games
Armored Core, a series featuring the eponymous robotic fighter under the player's control
Asheron's Call, a fantasy massively multiplayer online role-playing game

Aelod y Cynulliad, the title for Members of the National Assembly for Wales
Aircraftman, an air forces rank
Assistant Commissioner of Police of the Metropolis, a rank in London's Metropolitan Police
AC, a person appointed Companion of the Order of Australia

AC Cars, a British specialist automobile manufacturer
AC – The Danish Confederation of Professional Associations, an umbrella organisation for several Danish trade unions
AC Transit, a regional public transit agency in the San Francisco Bay Area
Action Congress, a political party in Nigeria
Ad Council Japan (AC Japan), an organization that distributes Japanese public service announcements
Air Canada, the flag carrier and largest airline of Canada by IATA code
Alternative for Change (Alternativa por el Cambio), a political party in Nicaragua
Associated Content, an online publisher and distributor of original content
Athletics Canada, the governing body of athletics in Canada
Ayala Corporation (Philippine Stock Exchange symbol), a holding company
Civic Alliance Foundation (Alianţa Civică), a Romanian non-governmental organization
Coast Alliance (Alianza Costeña), a former regional political coalition in Nicaragua

Acetyl, a functional group in chemistry
Actinium, a chemical element
Across corners (A/C), a measure of hexagonal nut external diameter
Alternating current, a type of electric current
- AC power, a net transfer of energy over a complete cycle of the alternating current waveform
Altocumulus, a medium level cloud type
Adenylate cyclase, a lyase enzyme
Anticipated convection, convective outlooks issued by the U.S. National Weather Service
Artificial consciousness, a field related to artificial intelligence and cognitive robotics
Axiom of choice, a mathematical set theory concept

Acromioclavicular joint (AC joint), the shoulder junction between the scapula and the clavicle
Anterior commissure
Anterior cruciate ligament (AC ligament or ACL), a major ligament in the knee
Appropriateness criteria (AC), when it is appropriate to perform a medical procedure or service
Chemotherapy regimens, adriamycin and cyclophosphamide, a chemotherapy regimen used to treat breast cancer
Assist control, a former term for continuous mandatory ventilation, a mode of mechanical ventilation

Ac (rune) (ᚪ), a rune of the Anglo-Saxon fuþorc and a continuation of the Elder Fuþark ansuz
Acre, a unit of area with the symbol ac
Advisory circular, a publication to provide guidance for compliance with airworthiness regulations
Appeal cases
Anarcho-capitalism, a form of free-market anarchism
Ante Christum or A.C., a Latin term meaning "before Christ"
Anthrocon, the largest furry convention in the world held in Pittsburgh, Pennsylvania
Assessment center, a process to evaluate candidates for a job
Average cost, in economics
Asphalt concrete, a type of road / path surfacing