Dictionary.com
Thesaurus.com
Jump To:
Synonyms

ac

1 American  

abbreviation

  1. acre; acres.


Ac 2 American  

abbreviation

Chemistry.
  1. acetate.

  2. acetyl.


Ac 3 American  
Symbol, Chemistry.
  1. actinium.


AC 4 American  

abbreviation

Electricity.
  1. alternating current.


A/C 5 American  
[ey-see] / ˈeɪˈsi /
Also AC, or a/c

abbreviation

  1. air conditioning.


A/C 6 American  
Or a/c

abbreviation

Bookkeeping.
  1. account.

  2. account current.


ac- 7 American  
  1. variant of ad- before c and qu: accede; acquire.


-ac 8 American  
  1. variant of -ic after Greek noun stems ending in i: cardiac; maniac.


a.c. 9 American  

abbreviation

  1. (in prescriptions) before meals.


A.C. 10 American  

abbreviation

  1. before Christ.


A.C. 11 American  

abbreviation

  1. Army Corps.

  2. Athletic Club.


a.c. 1 British  

abbreviation

  1. (in prescriptions) ante cibum

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

AC 2 British  

abbreviation

  1. alternating current Compare DC

  2. ante Christum

  3. Air Corps

  4. athletic club

  5. Companion of the Order of Australia

  6. appellation d'origine contrôlée: the highest French wine classification; indicates that the wine meets strict requirements concerning area of production, strength, etc See VDQS vin de pays vin de table

  7. Aelodau'r Cynulliad: Member of the Assembly (that is, the National Assembly of Wales)

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

ac 3 British  

abbreviation

  1. Ascension Island

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

A/C 4 British  

abbreviation

  1. Air Commodore

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

a/c 5 British  

abbreviation

  1. account

  2. account current

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Ac 6 British  

symbol

  1. actinium

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

AC Scientific  
  1. Abbreviation of alternating current


Etymology

Origin of -ac8

From Latin -acus, from Greek -akos

Origin of a.c.9

From Latin ante cibum

Origin of A.C.10

From Latin ante Christum

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Shortly after Khalife absconded from prison, at around 20:41 BST, Khan messaged his then-girlfriend Chowdhury's bank details and told her to "put 120£ in this ac… please thank u baby".

From BBC Jul. 21, 2026

He was a very well-known, established character ac even before "I Love Lucy."

From Fox News Jun. 5, 2021

Comparing not having A/C to 100 years ago when there was no ac is not a fair comparison.

From New York Times Aug. 15, 2016

For uniform circular motion, the acceleration is the centripetal acceleration— a = ac .

From Textbooks Aug. 12, 2015

Ngawang Doka replied in clear, sparkling English that carried a hint of a Canadian ac cent.

From "Into Thin Air" by Jon Krakauer

Balcarcel’s attorney, Samuel Simpson V, said Monday that he would be “very surprised” if Balcarcel Ac and Alvarado-Dubon were planning a mass shooting.

From Seattle Times Jul. 11, 2022

The affidavit was used to obtain a warrant to search a home in Richmond where Balcarcel Ac lived with a second man who was also arrested in connection with the alleged plot, Julio Alvarado-Dubon, 52.

From Seattle Times Jul. 8, 2022

Even to copy a relatively short paper, “Proc Nat Ac Sci”—“Proceedings of the National Academy of Sciences”—could take the better part of an hour.

From The New Yorker Jan. 6, 2020

Actinium, Ac, is the first member of the fourth transition series, which also includes Rf through Rg.

From Textbooks Feb. 14, 2019

Ac ofte him lyeþ þe wrench. feyr weder turneþ ofte in to reyne. ⁊ wunderliche makeþ his blench.

From Selections from early Middle English, 1130-1250 Part I: Texts by Joseph Hall

A broken car AC and soaring L.A. summer temperatures sent one writer on a search for cooling remedies and tonics.

From Los Angeles Times Sep. 2, 2026

But Mateta pushed to leave Palace in January this year and was close to joining AC Milan.

From BBC Aug. 22, 2026

Speaking after United's 4-2 friendly defeat by AC Milan on Saturday, defender Harry Maguire said he hoped Rashford would stay at Old Trafford because he is a "big asset" and a "huge threat".

From BBC Aug. 19, 2026

Appeared in the August 19, 2026, print edition as 'The Economic Case for European AC'.

From The Wall Street Journal Aug. 18, 2026

“Sorry. I don’t have access to AC that makes August feel like December.”

From "The Serpent King" by Jeff Zentner

Older APOE2 knock-in mice had smaller nucleoli, higher levels of the nuclear scaffolding protein Lamin A/C, and better-preserved heterochromatin in the hippocampus than mice carrying APOE3 or APOE4.

From Science Daily Jul. 24, 2026

Appeared in the July 25, 2026, print edition as 'Notable & Quotable: A/C'.

From The Wall Street Journal Jul. 24, 2026

A team led by Hong Kong researchers recently created an A/C alternative that achieved a cooling power of 1,284W—the first time an elastocaloric device surpassed the 1,000W mark.

From BBC May 19, 2025

“Twenty-five classrooms without A/C on just Day One of 100-plus-degree weather,” one teacher told the board.

From Los Angeles Times Nov. 27, 2023

Roy waited inside for a while, but without A/C it was unbearably hot and sticky.

From "Hoot" by Carl Hiaasen

Still, with the prices of many commodities climbing, the companies couldn’t ac- commodate price shocks, so they often  wound  up hiring banks to hedge their vulnerability to volatile product markets.

From MSNBC Jun. 4, 2014

“I suppose the problem at the moment is that we don’t have a one- to-one mapping, because even our best theories aren’t completely ac- curate,” Ladyman said.

From Scientific American Jan. 31, 2014

She is all that is artistic without being vulgar and is the one ac- tress today who can wink without being suggestive.

From Time Magazine Archive

The government has devised civic ac- tion programs to rebuild damaged hamlets, and anti-guerrilla patrols are often accompanied by doctors who bring free medical care to the hill people.

From Time Magazine Archive

NOTE.—The forms ac-, af-, etc., are euphonic variations of ad-, and follow generally the rule that the final consonant of the prefix assimilates to the initial letter of the root.

From New Word-Analysis by William Swinton

NOTE.—The suffix -ac is found only in Latin derivatives of Greek origin.

From New Word-Analysis by William Swinton

A new report finds that about 3% of autos--high- and low-end models--have fungi and bacteria breeding in the moisture that collects on the a.c.

From Time Magazine Archive

The 60 h.p. has parallel a.c. cylinders, the other two are radial w.c.

From Jane's All the World's Aircraft 1913 by Various

It turned out that all electricity here was d.c., conjured up by commanding the electrons in a wire to move in one direction, and completely useless with a.c. motors.

From The Sky Is Falling by Lester Del Rey

These writings are said to date from about 97 to 150 a.c.

From Frauds and Follies of the Fathers A Review of the Worth of their Testimony to the Four Gospels by Joseph Mazzini Wheeler

In the third century a.c. he composed in Greek a history of his native land, which has perished.

From Myths of Babylonia and Assyria by Donald Alexander Mackenzie

Other historical Pasadena figures in the book include the bookseller A.C.

From The Wall Street Journal Feb. 27, 2026

But the filmmaking team is fairly confident it belongs to Irvine, due to the sock found inside the boot being embroidered with the words "A.C. Irvine".

From BBC Oct. 11, 2024

The company was born in the garage of A.C.

From Seattle Times Apr. 22, 2024

In 2022, James and Drake also invested in A.C.

From New York Times Mar. 4, 2024

The 1st A.C. lay back, as has been explained, almost at right angles to the line of the canal, along the two roads that branch off from Mons to Beaumont and Maubeuge respectively.

From The First Seven Divisions Being a Detailed Account of the Fighting from Mons to Ypres by Ernest W. Hamilton

Chris Coucheron-Aamot, a guest at the Sandals resort, wrote on Facebook that the cause of the episode “may have been a fault with the a/c in the unit, causing a toxic coolant leak.”

From Seattle Times May 9, 2022

If that power comes from fossil fuels, a/c alone will account for a half-degree Celsius rise in global temperatures.

From The Guardian Aug. 11, 2019

Not a single prison should get a/c before all the schools in our nation have a/c.

From New York Times Aug. 20, 2016

Everyone drives huge SUVs, the houses have no insulation, heating on all winter, a/c on all summer, landfills are overflowing, you get punished for reusing shopping bags.

From BBC Jul. 10, 2011

Now the question is, Is this the spirit and meaning of the a/c now furnished?*

From Charles Lever, His Life in His Letters, Vol. I by Edmund Downey

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training