Ab

.
Nautical, .
.
U.S. Air Force. Airman Basic.
Alberta, Canada (approved for postal use).
antiballistic; antiballistic missile.
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.
Chemistry, .
Immunology, .
a formal element occurring in loanwords from Latin, where it meant “away from”:
abdicate; abolition.
.
Baseball. (times) at bat.
.
Nautical, .
Baseball. (times) at bat.
Also, a.b.
abdominal muscles.
Contemporary Examples

Ab 32, the law Whitman wants to suspend, is nearly as popular as free cerveza.
The GOP’s Big Green Gamble Joe Mathews December 7, 2009

Ab shooting in car: “Only guns will free us from the past.”
Terrorist Chic The Daily Beast October 7, 2008

On 27 July 2013, Ab Neubauer reported that she was sexually assaulted the previous evening.
Spies, Lies, and Rape in the Air Force: An Undercover Agent’s Story Jacob Siegel March 3, 2014

The AbT has a saying on the inside, “If you ever disrespect the Ab, we will make sure you leave in a body bag.”
The Aryan Brotherhood of Texas: ‘Brutal, Deadly, and Effective’ Seth Ferranti April 3, 2013

“Ab Welsh, who was a forward with the Saskatoon Quakers was the first one,” Howe said.
Gordie Howe Hockey’s Greatest War Horse W.C. Heinz May 30, 2014

Historical Examples

Having determined this distance, the weight on Ab was removed and the aerodrome was allowed to regain its former position.
Langley Memoir on Mechanical Flight, Parts I and II S. P. (Samuel Pierpont) Langley and Charles M. (Charles Matthews) Manly

A character mentioned in the MAbinogion, goes by the name of Gwyddneu Ab Llwydau.
Y Gododin Aneurin

Sacramento, dum praedictus versus Tantum ergo dicitur, Ab omnibus omnino persistendum erit in inclinatione usque ad cernui.
The Irish Ecclesiastical Record, Volume 1, December 1864 Various

Arthwys son of Ceneu Ab Coel was too early for the battle of Cattraeth.
Y Gododin Aneurin

We get the same temporary current in cd as we would if we should place the coils parallel and then start the current in Ab.
Letters of a Radio-Engineer to His Son John Mills

noun
a variant of Av
abbreviation
Also a.b.. able-bodied seaman
(in the US) Bachelor of Arts
(esp in postal addresses) Alberta (Canada)
symbol
a human blood type of the ABO group, containing both the A antigen and the B antigen
plural noun
(informal) abdominal muscles
abbreviation
acrylonitrile-butadiene-styrene: any of a range of tough copolymers used esp for making moulded articles
prefix
away from; off; outside of; opposite to: abnormal, abaxial, aboral
prefix
denoting a cgs unit of measurement in the electromagnetic system: abvolt

word-forming element meaning “away, from, from off, down;” from Latin ab-, ab “off, away from,” from PIE root *apo- (see apo-). Reduced to a- before -m-, -p-, or -v-; sometimes abs- before -c- or -t-.
n.

colloquial shortening of abdominals, by 1992.

Ab abbr.
antibody

ab- 2
pref.
Used to indicate an electromagnetic unit in the centimeter-gram-second system: abcoulomb.

ab- 1
pref.
Away from: abaxial.
Abkhazian
antibody
able-bodied [seaman]
about (shortwave transmission)
airbase
airman basic
Alberta
Latin Artium Baccalaureus (Bachelor of Arts)
at bats (baseball)
about
abbreviation
abdominal muscles
absolute temperature
American Board of Surgery
Animal Behavior Society
antilock braking system