AC

See also: Appendix:Variations of "ac"

Translingual

Symbol

AC

1. (international standards) Exceptionally reserved ISO 3166-1 alpha-2 country code for Ascension Island.

   Synonym: ASC (alpha-3)

Usage notes

This is an exceptionally reserved code, included as part of ISO 3166-1 on the request of the Universal Postal Union for the purpose of assigning a stamp issuing area, and is not endorsed for general use by the ISO outside of that purpose.

English

Alternative forms

• (air conditioning) a.c., A/C, a/c
• (alternating current) A.C., a.c., ac
• (army corps, athletic club) A.C.
• (anno Christi, ante Christum) A.C., A. C.
• (ante cibum) a.c.

Noun

AC (countable and uncountable, plural ACs)

1. (aviation) Initialism of absolute ceiling.
2. Initialism of access control.

   Hyponym: RBAC

3. (finance) Initialism of account current.
4. (anatomy) Initialism of anterior chamber.
5. (music, radio) Initialism of adult contemporary (a radio format).
6. (biochemistry) Initialism of adenylyl cyclase.
7. (medicine) Initialism of adjuvant chemotherapy.
   • 2018, Gollins S et al., “A prospective phase II study of pre-operative chemotherapy then short-course radiotherapy for high risk rectal cancer: COPERNICUS”, in British Journal of Cancer‎^[1]:

     Current UK practice, supported by NICE guidance is to complete local pelvic treatment with surgery±pre-operative radiotherapy, before considering systemic adjuvant chemotherapy (AC)

9. (uncountable) Initialism of air conditioning.
10. (countable) Initialism of air conditioner.
    • 1997 June 18, Brooks Taylor, “AC/Heat from ground?”, in sci.engr.heat-vent-ac‎^[2] (Usenet), archived from the original on 1 July 2026:

      Our summer electric bill is around $120/month just from using 15,000 and 10,000 btu ACs.

    • 2020 June 29, Doug Mahoney, Harry Sawyers, “The Best Ductless Mini Split Air Conditioner”, in Wirecutter‎^[3], New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 25 July 2020:

      If you want to cool or heat specific rooms with better efficiency, more power, and less clutter than window ACs and space heaters—and less complexity than central HVAC—consider a mini-split system.

    • 2026 June 30, Chas Danner, “Europe’s Great AC Debate: Highlights, Hot Takes, and Hysteria”, in Intelligencer‎^[4], New York, N.Y.: New York Media, →ISSN, →OCLC, archived from the original on 30 June 2026:

      Fewer than 20 percent of Europeans have air-conditioning, as opposed to nearly 90 percent of Americans, and while you’d think Europe’s governments and people would be rushing to fully integrate ACs into their cooling arsenal, that’s no simple task for a variety of reasons.

11. Initialism of air corps.
12. Initialism of aircraftman.
14. (electricity) Initialism of alternating current (often used to indicate an alternating potential rather than a current).

    Coordinate term: DC

    110 V AC

    1. (electricity, informal, by extension) supply of electric energy via a public electricity grid [c. 1900]
15. Initialism of area code.
16. Initialism of army corps.
17. Initialism of athletic club.
18. Initialism of author's correction.
19. Initialism of automobile club.
20. (US, military) Initialism of Auxiliary Collier (a naval coal transport that travels with the fleet to provide coal for coal-powered warships).
21. (set theory) Initialism of axiom of choice.
22. (UK, law enforcement) Initialism of assistant commissioner, a police rank used in London's Metropolitan Police.
23. (Australia) Companion of the Order of Australia.
24. Initialism of aviation cadet.
25. (chemistry) Initialism of ammonium chloride.
26. (geography) Initialism of autonomous county.
27. (roleplaying games) Initialism of armor class.
28. (autism, psychology) singular of ACs (“autistics and cousins”).
29. (prison) Initialism of administrative custody.
    • 1988 February 7, Delana Emery, “Women Prisoners On Hunger Strike For Equal Rights”, in Gay Community News, volume 15, number 29, page 5:

      We the women in A.C. are on a hunger strike.

30. (Anglicanism) Initialism of Anglo-Catholic.
31. Initialism of asphalt concrete.
32. Initialism of asphalt cement.
33. Initialism of asphalt content.

Derived terms

• AC/DC

Translations

alternating current

• Dutch: wisselstroom (nl)
• Finnish: vaihtovirta (fi)
• German: Wechselstrom (de) m
• Indonesian: arus bolak-balik
• Japanese: 交流 (ja) (こうりゅう, kōryū)
• Korean: 교류(交流) (ko) (gyoryu)
• Polish: prąd zmienny, prąd przemienny
• Portuguese: CA (pt) f
• Romanian: curent alternativ (ro) m, c.a.
• Russian: переме́нный ток (ru) m (pereménnyj tok)
• Spanish: CA, corriente alterna
• Swedish: AC (sv), växelström (sv) c

alternating potential

• Dutch: wisselspanning (nl)
• German: Wechselspannung

Adjective

AC (not comparable)

1. (anatomy, medicine) Initialism of acromioclavicular.

   AC joint;  AC separation

2. Initialism of air conditioned.
3. (religion) Initialism of antichristian.

Adverb

AC (not comparable)

1. Initialism of anno Christi (in the year of Christ).
2. Initialism of ante Christum, (before Christ).

Synonyms

• (anno Christi): AD (anno Domini)
• (ante Christum): BC (before Christ)

Antonyms

• (antonym(s) of “ante Christum”): AD (anno Domini)

Phrase

AC

1. Initialism of all clear (as in button on electronic calculator).
2. (medicine) Initialism of ante cibum (before meals).
3. (law) Initialism of as charged, as in: guilty as charged, usually a/c.

Proper noun

AC

1. Abbreviation of Aceh: a province of Indonesia.
2. Abbreviation of Acre: a state of Brazil.
3. Initialism of America's Cup (competition yacht sailing match racing regatta).
4. (law) Initialism of Appeal Cases (a subseries of Incorporated Council of Law Reporting's Law Reports).

Derived terms

• (America's Cup):
  • IACC
  • AC72
  • AC45
  • AC90

Verb

AC (third-person singular simple present ACs, present participle ACing, simple past and past participle ACed)

1. Initialism of air-condition.
   • 1997 June 18, Brooks Taylor, “AC/Heat from ground?”, in sci.engr.heat-vent-ac‎^[5] (Usenet), archived from the original on 1 July 2026:

     My heating and cooling bills were within reason for the past 3 years. We only ran the AC/Heat from 6pm to midnight, but with the arrival of my son and mother-inlaw^[sic] we must heat and AC 24 hrs a day.

   • 2002 August 11, shawn811, “HELP: 2002 Civic, can't turn off AC in defog mode. Outside = -30C don't want to AC the air then heat it. Its^[sic] cold enough outside.”, in rec.autos.makers.honda‎^[6] (Usenet), archived from the original on 1 July 2026
   • 2008 June 22, ~~NoMad~~, “An amazing AC unit”, in alt.energy.homepower‎^[7] (Usenet), archived from the original on 1 July 2026:

     I've been thinking of getting a little 6000BTU unit to AC my bedroom so I can venture into lower altitudes during the summer.

Anagrams

• ca, CA, C.A., ca., &ca., &ca

Chinese

simp. and trad. (AC)		A	C

Etymology

Borrowed from English account. Doublet of account.

Pronunciation

• Cantonese (Jyutping): ei¹ si¹

---

• Cantonese
  • (Standard Cantonese, Guangzhou–Hong Kong)⁺
    • Jyutping: ei¹ si¹
    • Yale: ēi sī
    • Cantonese Pinyin: ei¹ si¹
    • Guangdong Romanization: éi¹ xi¹
    • Sinological IPA ^(key): /ei̯⁵⁵ siː⁵⁵/

Noun

AC

1. (Hong Kong Cantonese, computing) account

   冇AC都可以 [Cantonese]  ―  mou⁵ AC dou¹ ho² ji⁵ [Jyutping]  ―  don't need an account

Alternative forms

• ac

Related terms

• account

Italian

Noun

AC

1. anno Christi
2. associazione calcio (football/soccer club)

   AC Milan

   (please add an English translation of this usage example)

Adjective

AC (invariable)

1. avanti Cristo

Anagrams

• ca, ca'

Japanese

Noun

AC(アーケード) • (ākēdo) 

1. (only in compounds) abbreviation of アーケード (“arcade, establishment with coin-operated games”)

   AC(アーケード)音( おと)ゲー

   ākēdo otogē

   arcade rhythm game

Latin

Alternative forms

• A. C.

Phrase

AC

1. ante Christum
2. anno Christi

Synonyms

• 1.: a. Chr. n, a. C. n., a. Chr.
• 2.: A. D., A.D., AD; p. Chr. n., p. C. n., p. Chr.

References

• “AC”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “AC”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.

Polish

Pronunciation

• IPA^(key): /aˈt͡sɛ/
• Rhymes: -ɛ
• Syllabification: A‧C

Noun

AC n (indeclinable)

1. abbreviation of autocasco

Further reading

• “AC”, in Wielki słownik języka polskiego‎^[8] (in Polish), Instytut Języka Polskiego PAN
• “AC”, in Polish dictionaries at PWN‎^[9] (in Polish)

Portuguese

Proper noun

AC

1. abbreviation of Acre: a state of Brazil

Further reading

• “AC”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “AC”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Welsh

Pronunciation

• (North Wales) IPA^(key): /ˌeɨ̯lɔd kəˈnɨ̞ɬjad/
• (South Wales) IPA^(key): /ˌei̯lɔd kəˈnɪɬjad/

Noun

AC m (plural ACau)

1. (politics) initialism of Aelod Cynulliad