AR
Abbreviation with 10 meanings
| Stands for | Arkansas |
|---|---|
| Meanings | 10 |
| Categories | Geography & Places, Medical, Technology & Computing, Business & Finance, Science & Engineering, Sports |
| Also written | Ar |
AR has ten meanings. The most common are Arkansas (US state) and Allergic rhinitis (ophthalmology & ENT); it can also stand for Augmented reality, Accounts receivable, Argentina, Argon and Aortic regurgitation, plus 3 more listed below.
Meanings of AR at a glance
| # | AR stands for | Context |
|---|---|---|
| 1 | Arkansas | Geography & Places › US State |
| 2 | Allergic rhinitis | Medical › Ophthalmology & ENT |
| 3 | Augmented reality | Technology & Computing › Consumer Electronics |
| 4 | Accounts receivable | Business & Finance › Accounting |
| 5 | Argentina | Geography & Places › Country Code |
| 6 | Argon | Science & Engineering › Chemical Element |
| 7 | Aortic regurgitation | Medical › Cardiology |
| 8 | Autosomal recessive | Science & Engineering › Genetics |
| 9 | Aspect ratio | Technology & Computing › Consumer Electronics |
| 10 | Assistant referee | Sports › Soccer (Association Football) |
1. Arkansas
Geography & Places · US State Abbreviations
Southern state admitted as the 25th state on June 15, 1836, nicknamed the Natural State. Little Rock is the capital and largest city, Hot Springs National Park lies in the Ouachita Mountains, and Bentonville in the northwest corner is the headquarters of Walmart.
Example: Please update my billing address to 1200 Main St, Little Rock, AR 72201.
Traditional and AP form: Ark., used by AP in datelines (FAYETTEVILLE, Ark.) and party labels like R-Ark. AR has been the postal code since 1963 and is often confused with Arizona (AZ) or Alaska (AK); outside the US, AR is Argentina's ISO code. An 1881 legislative resolution fixed the pronunciation AR-kan-saw, unlike the Arkansas River, which many Kansans call ar-KAN-zus.
2. Allergic rhinitis
Medical · Ophthalmology & ENT Abbreviations
Inflammation of the nasal lining triggered by inhaled allergens such as pollen, dust mites, mold or animal dander, causing sneezing, itching, runny nose and congestion. It may be seasonal (hay fever) or year-round and often coexists with asthma and eye allergies.
Example: Seasonal AR with itchy eyes, worse in spring; fluticasone nasal spray daily and cetirizine as needed.
Intranasal corticosteroids are the most effective single treatment, and many are available over the counter. Allergen immunotherapy, by injections or under-the-tongue tablets, can modify the disease. Despite the name, hay fever involves neither hay nor fever. In cardiology AR means aortic regurgitation.
3. Augmented reality
Technology & Computing · Consumer Electronics Abbreviations
Technology that overlays digital images, text or 3D objects onto a live view of the real world, through a phone camera, smart glasses or a headset. Uses include games, navigation, shopping previews and industrial maintenance.
Example: The furniture app uses AR to show how the sofa would look in your living room.
Boeing researcher Tom Caudell is credited with coining the term around 1990. Pokémon Go (2016) introduced AR to hundreds of millions of players, and Apple's ARKit (2017) and Google's ARCore (2018) brought it to phone apps. Smart glasses that display information in the wearer's view remain an evolving category. Unlike VR, AR keeps the real world visible.
4. Accounts receivable
Business & Finance · Accounting Abbreviations
Money owed to a company by customers for goods or services delivered on credit, recorded as a current asset on the balance sheet. The AR function invoices customers, applies payments and chases overdue balances.
Example: AR is up 20 percent because two large distributors are paying in 75 days instead of 45.
Also written A/R. An AR aging report groups unpaid invoices by how long they are overdue, such as 0-30, 31-60 and 61-90 days, and helps estimate the allowance for doubtful accounts. Companies can turn receivables into cash early through factoring. Elsewhere, AR means augmented reality or the state of Arkansas.
5. Argentina
Geography & Places · Country Code Abbreviations
Argentine websites end in .ar and the peso trades as ARS, both built on Argentina's two-letter code. Buenos Aires is the capital and ARG the alpha-3 code of the eighth-largest country in the world by area.
Example: Payment failed because the card was issued in AR and the store only accepts US cards.
In US addresses AR is Arkansas. In language tags ar is Arabic, not Argentina, so ar-AR is not meaningful while es-AR means Spanish as used in Argentina. AR also means augmented reality.
6. Argon (Ar)
Science & Engineering · Chemical Element Abbreviations
Argon makes up about 0.93% of Earth's atmosphere, making this noble gas (element 18) the third most abundant gas in air after nitrogen and oxygen. Because it is inert and cheap, argon shields welds from oxidation, fills incandescent bulbs and insulated windows, and protects reactive materials in laboratory glove boxes.
Example: Set the shielding gas to pure Ar at 20 cubic feet per hour for TIG welding aluminum.
Lord Rayleigh noticed that nitrogen extracted from air was slightly denser than nitrogen made chemically, and with William Ramsay he isolated argon in 1894; both received Nobel Prizes in 1904. The name is Greek argos, "idle" or "lazy," for its refusal to react. Its symbol was simply A until IUPAC changed it to Ar in 1957.
7. Aortic regurgitation
Medical · Cardiology Abbreviations
Leakage of blood from the aorta back into the left ventricle during diastole, caused by valve disease (bicuspid valve, endocarditis, rheumatic disease) or a dilated aortic root. Chronic AR causes gradual volume overload, while acute AR, for example from aortic dissection, is a surgical emergency.
Example: Blowing early diastolic decrescendo murmur at the left sternal border; echo shows moderate AR with a dilated root.
Interchangeable with AI (aortic insufficiency). Physical signs of severe chronic AR include a wide pulse pressure, a bounding "water-hammer" (Corrigan) pulse and head bobbing (de Musset sign). Surgery is advised for severe AR with symptoms, an ejection fraction of 55 percent or less, or progressive ventricular dilation.
8. Autosomal recessive
Science & Engineering · Genetics Abbreviations
Inheritance pattern in which a disorder appears only when a person inherits two altered copies of a gene on a non-sex chromosome, one from each parent. Carrier parents are usually unaffected and have a 25% chance with each pregnancy of an affected child, as in cystic fibrosis and sickle cell disease.
Example: Both siblings were affected while the parents were healthy, suggesting AR inheritance.
Recessive conditions are more frequent in populations with founder effects or consanguinity, which is why carrier screening programs target diseases such as Tay-Sachs in specific communities. About one in 25 people of Northern European descent carries a cystic fibrosis variant. Ar is also the chemical symbol for argon.
9. Aspect ratio
Technology & Computing · Consumer Electronics Abbreviations
Proportional relationship between the width and height of an image, screen or video frame, written as two numbers such as 16:9 or 4:3. Camera menus, video editors and AI image generators abbreviate it AR.
Example: Set the AR to 9:16 for vertical videos on TikTok and Reels.
Common ratios include 4:3 (old TVs and many tablets), 16:9 (HD and 4K TVs), 21:9 (ultrawide monitors) and 2.39:1 (widescreen cinema). Showing content in the wrong ratio produces black bars (letterboxing or pillarboxing) or stretched pictures. Image generators such as Midjourney accept a parameter like "--ar 16:9". Context separates this from augmented reality.
10. Assistant referee
Sports · Soccer (Association Football) Abbreviations
Official who runs the touchline and signals offside, throw-ins, corners and fouls with a flag. Each match normally has two assistant referees.
Example: The AR raised his flag late, and VAR confirmed the offside.
Called linesmen until the title changed in 1996. A fourth official manages substitutions and technical areas. In US geography AR is the postal code for Arkansas, and in technology it means augmented reality.
Related abbreviations
More US state abbreviations
- AK – Alaska
- AL – Alabama
- AZ – Arizona
- CA – California
- CO – Colorado
- CT – Connecticut
- DC – District of Columbia
- DE – Delaware
See all 51 US state abbreviations →
More ophthalmology & ENT abbreviations
- ADD – Near addition (add power)
- AMD – Age-related macular degeneration
- anti-VEGF – Anti-vascular endothelial growth factor
- AOM – Acute otitis media
- AREDS – Age-Related Eye Disease Study
- ARMD – Age-related macular degeneration
- BCVA – Best-corrected visual acuity
- BOM – Bilateral otitis media
See all 74 ophthalmology & ENT abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.