Meanings
ac1
plural acs
- account; money of account
- abbreviationAbbreviation of acre.
- Alternative letter-case form of AC (“air conditioning”).
- businessAlternative letter-case form of AC (“alternating current”).
- not comparablemedicineante cibum, before meals
AC2
plural ACs · alternative a.c. · alternative A/C · alternative a/c · alternative A.C. · alternative a.c. · alternative ac · alternative A.C. · alternative A.C. · alternative A. C. · alternative a.c.
- abbreviationcountableinitialismuncountableaeronauticsInitialism of absolute ceiling.
- abbreviationcountableinitialismuncountableInitialism of access control.
- abbreviationcountableinitialismuncountablebusinessInitialism of account current.
- abbreviationcountableinitialismuncountableanatomyInitialism of anterior chamber.
- abbreviationcountableinitialismuncountablebroadcastingInitialism of adult contemporary (a radio format).
- abbreviationcountableinitialismuncountablebiochemistryInitialism of adenylyl cyclase.
- abbreviationcountableinitialismuncountablemedicineInitialism of adjuvant chemotherapy.
Current UK practice, supported by NICE guidance is to complete local pelvic treatment with surgery±pre-operative radiotherapy, before considering systemic adjuvant chemotherapy (AC)
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 - abbreviationinitialismuncountableInitialism of air conditioning.
- abbreviationcountableinitialismInitialism of air conditioner.
Our summer electric bill is around $120/month just from using 15,000 and 10,000 btu ACs.
1997 June 18, Brooks Taylor, “AC/Heat from ground?”, in sci.engr.heat-vent-ac (Usenet), archived from the original on 01 Jul 20262 more examples
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.
2020 June 29, Doug Mahoney, Harry Sawyers, “The Best Ductless Mini Split Air Conditioner”, in Wirecutter, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 25 Jul 2020Fewer 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.
2026 June 30, Chas Danner, “Europe’s Great AC Debate: Highlights, Hot Takes, and Hysteria”, in Intelligencer, New York, N.Y.: New York Media, →ISSN, →OCLC, archived from the original on 30 Jun 2026 - abbreviationcountableinitialismuncountableInitialism of air corps.
- abbreviationcountableinitialismuncountableInitialism of aircraftman.
- abbreviationcountableinitialismuncountablebusinessInitialism of alternating current (often used to indicate an alternating potential rather than a current).
110 V AC
- broadlycountableinformaluncountablebusinesssupply of electric energy via a public electricity gridFirst known use c. 1900
- abbreviationcountableinitialismuncountableInitialism of area code.
- abbreviationcountableinitialismuncountableInitialism of army corps.
- abbreviationcountableinitialismuncountableInitialism of athletic club.
- abbreviationcountableinitialismuncountableInitialism of author's correction.
- abbreviationcountableinitialismuncountableInitialism of automobile club.
- abbreviationcountableinitialismuncountablemathematicsInitialism of axiom of choice.
- UKabbreviationcountableinitialismuncountablegovernmentInitialism of assistant commissioner, a police rank used in London's Metropolitan Police.
- AustraliacountableuncountableCompanion of the Order of Australia.
- abbreviationcountableinitialismuncountableInitialism of aviation cadet.
- abbreviationcountableinitialismuncountablechemistryInitialism of ammonium chloride.
- abbreviationcountableinitialismuncountablegeographyInitialism of autonomous county.
- countablesingularuncountableautismhuman sciencessingular of ACs (“autistics and cousins”).
- abbreviationcountableinitialismuncountableprisonInitialism of administrative custody.
We the women in A.C. are on a hunger strike.
1988 February 7, Delana Emery, “Women Prisoners On Hunger Strike For Equal Rights”, in Gay Community News, volume 15, number 29, page 5 - abbreviationcountableinitialismuncountableAnglicanismInitialism of Anglo-Catholic.
- abbreviationcountableinitialismuncountableInitialism of asphalt cement.
- abbreviationcountableinitialismuncountableInitialism of asphalt content.
alternative a.c. · alternative A/C · alternative a/c · alternative A.C. · alternative a.c. · alternative ac · alternative A.C. · alternative A.C. · alternative A. C. · alternative a.c.
- abbreviationinitialismnot comparableInitialism of air conditioned.
- abbreviationinitialismnot comparablelifestyleInitialism of antichristian.
alternative a.c. · alternative A/C · alternative a/c · alternative A.C. · alternative a.c. · alternative ac · alternative A.C. · alternative A.C. · alternative A. C. · alternative a.c.
alternative a.c. · alternative A/C · alternative a/c · alternative A.C. · alternative a.c. · alternative ac · alternative A.C. · alternative A.C. · alternative A. C. · alternative a.c.
- abbreviationinitialismInitialism of all clear (as in button on electronic calculator).
- abbreviationinitialismmedicineInitialism of ante cibum (before meals).
alternative a.c. · alternative A/C · alternative a/c · alternative A.C. · alternative a.c. · alternative ac · alternative A.C. · alternative A.C. · alternative A. C. · alternative a.c.
- abbreviationinitialismInitialism of America's Cup (competition yacht sailing match racing regatta).
- abbreviationinitialismlawInitialism of Appeal Cases (a subseries of Incorporated Council of Law Reporting's Law Reports).
present singular third person ACs · participle present ACing · participle past ACed · past ACed · alternative a.c. · alternative A/C · alternative a/c · alternative A.C. · alternative a.c. · alternative ac · alternative A.C. · alternative A.C. · alternative A. C. · alternative a.c.
- abbreviationinitialismInitialism of air-condition.
I've been thinking of getting a little 6000BTU unit to AC my bedroom so I can venture into lower altitudes during the summer.
2008 June 22, ~~NoMad~~, “An amazing AC unit”, in alt.energy.homepower (Usenet), archived from the original on 01 Jul 20261 more example
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.
1997 June 18, Brooks Taylor, “AC/Heat from ground?”, in sci.engr.heat-vent-ac (Usenet), archived from the original on 01 Jul 2026
Ac3
plural Acs
- slangAfrican-American VernacularThe Acura Legend automobile.
With the Mac in the Ac door paneling
1994, Notorious B.I.G., Unbelievable
- abbreviationinitialismInitialism of air-conditioning.
- abbreviationinitialismclimatologyInitialism of altocumulus cloud.
- abbreviationAbbreviation of acetate.
- abbreviationAbbreviation of acetyl.
Synonyms & antonyms
More synonyms by meaning
nounan electric current that reverses direction sinusoidally
nouna radioactive element of the actinide series; found in uranium ores
Synonym sets from Open English WordNet, CC BY 4.0.
Origin
Abbreviation.
Full word history & related roots →Translations
Dutch wisselstroom, wisselspanning
- wisselstroomalternating current
- wisselspanningalternating potential
Finnish vaihtovirta
- vaihtovirtaalternating current
German Wechselstrom, Wechselspannung
- Wechselstromalternating current
- Wechselspannungalternating potential
Indonesian arus bolak-balik
- arus bolak-balikalternating current
Japanese 交流
- 交流 (kōryū)alternating current
Korean 교류
- 교류 (gyoryu)alternating current
Polish prąd zmienny, prąd przemienny
- prąd zmiennyalternating current
- prąd przemiennyalternating current
Portuguese CA
- CAalternating current
Romanian curent alternativ, c.a.
- curent alternativalternating current
- c.a.alternating current
Russian переме́нный ток
- переме́нный ток (pereménnyj tok)alternating current
Spanish CA, corriente alterna
- CAalternating current
- corriente alternaalternating current
Swedish AC, växelström
- ACalternating current
- växelströmalternating current
Cite this entry
ac. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/ac
“ac.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/ac. Accessed November 2, 2026.
WatkinsX Dictionary, s.v. “ac,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/ac.
Source: ac on Wiktionary, CC BY-SA 4.0.