Ab

¹ American  

[ahb, ahv] / ɑb, ɑv /

noun

1. Av.

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Ab ² American  

Symbol.

1. Chemistry. alabamine.

2. Immunology. antibody.

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AB ³ American  

abbreviation

1. Nautical. able seaman.

2. airborne.

3. U.S. Air Force. Airman Basic.

4. Alberta, Canada (approved for postal use).

5. antiballistic; antiballistic missile.

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AB ⁴ American  

Symbol, Physiology.

1. a major blood group usually enabling a person whose blood is of this type to donate blood to persons of type AB and to receive blood from persons of type O, A, B, or AB.

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ab- ⁵ American  

1. a formal element occurring in loanwords from Latin, where it meant “away from”.

   abdicate; abolition.

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ab. ⁶ American  

abbreviation

1. about.

2. Baseball. (times) at bat.

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A.B. ⁷ American  

abbreviation

1. Bachelor of Arts.

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A.B. ⁸ American  

abbreviation

1. Nautical. able seaman.

2. Baseball. (times) at bat. Also a.b.

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AB ¹ British  

abbreviation

1. Also: a.b..  able-bodied seaman

2. (in the US) Bachelor of Arts

3. (esp in postal addresses) Alberta (Canada)

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symbol

1. a human blood type of the ABO group, containing both the A antigen and the B antigen

Ab ² British  

/ æb /

noun

1. a variant of Av

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ab- ³ British  

prefix

1. away from; off; outside of; opposite to

   abnormal

   abaxial

   aboral

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ab- ⁴ British  

prefix

1. denoting a cgs unit of measurement in the electromagnetic system

   abvolt

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Etymology

Origin of ab-⁵

< Latin ab (preposition and prefix) from, away, cognate with Greek apó, Sanskrit ápa, German ab, English of ¹, off

Origin of A.B.⁷

< New Latin, Medieval Latin Artium Baccalaureus

Explanation

An ab is a stomach, or abdominal, muscle. Doing sit ups and crunches will help you tone your abs. Ab is shorthand for abdominal, which comes from the Latin abdomen, "belly," and it's a common name for what's formally known as the rectus abdominus muscle. Your abs run up and down the front of your torso, on either side of your belly button. In extremely fit or muscly people with little body fat, you can actually see how the abs are separated into several sections, the so-called "six-pack."

Example Sentences

The testosterone-based view of Ab Ex is entrenched, but recent scholarship has focused attention elsewhere.

From The Wall Street Journal • Feb. 28, 2026

So it felt like Ab to Abby was a very cute jump.

From Salon • Jun. 29, 2025

Mr Abdallah, who lost his brother, said Ab Shouk camp’s Al Saalam School was now doubling as a shelter for those who had recently lost their homes.

From BBC • May 23, 2024

More to the point, while loose, brushy, sometimes energetic paint-handling is on vibrant display, as it was in the Ab Ex heyday, the way he puts that technique to work is what matters most.

From Los Angeles Times • Dec. 8, 2022

Everyone calls him The Abbot or Ab Sheehan and no one knows why.

From "Angela's Ashes: A Memoir" by Frank McCourt