AST

AST is a three-letter abbreviation that stands for a number of different things.

In science and technology

• Abstract syntax tree, a finite, labeled, directed tree used in computer science
• Andrew S. Tanenbaum, a computer scientist (often uses this acronym as his identifier)
• Asynchronous System Traps, a mechanism used in several computer operating systems

In medicine

• Aspartate transaminase (aka SGOT), an enzyme associated with liver parenchymal cells. AST values are checked in blood tests
• Agitated saline test (agitated saline contrast test), a diagnostic heart procedure

In mathematics

• Alternating series test, a method used to prove that infinite series of terms converge
• Alternative set theory, an alternative mathematical approach to the concept of set

Organisations and companies

• Allied Security Trust, a patent holding company
• AST Research, a defunct personal computer manufacturer
• Association for Software Testing, a nonprofit organization dedicated to advancing software testing
• AST (publisher)
• AST, American Sensor Technologies, Inc., A sensor manufacturing company
• AST, Airborne Surveillance Technician aboard the USAF E-3, Cooks food and delivers water to USAF crewmembers.

In education

• Ameson Scholastic Test, originally designed for Chinese students applying to the University of Cambridge in the UK, and now used by a handful of UK and Australian universities
• ACT Scaling Test, a series of aptitude tests taken by Year 12 students in ACT, Australia
• Alpha Sigma Tau, a national collegiate sorority of the United States
• Atlantic School of Theology, an ecumenical university in Atlantic Canada
• Conroe ISD Academy of Science and Technology, a specialized magnet school of science and technology in Conroe, Texas
• Avalanche Skills Training, a standardized form of avalanche training in Canada
• American School of Tegucigalpa
• Advanced Skills Teacher - a specific type of teaching role in England and Wales
• Associate in Specialized Technology, a type of Associate's degree

In politics and government

• Office of Commercial Space Transportation, a branch of the US Federal Aviation Administration
• Aviation Survival Technician, a United States Coast Guard rating
• Alaska State Troopers, the state police force for the State of Alaska
• Chadian Social Action (Action Sociale Tchadienne), a defunct Chadian political party

In transport

• Astoria Regional Airport, a public airport of Clatsop County, Oregon, USA (FAA Identifier: AST)
• Aston railway station, a railway station in Aston in Birmingham, England (National Rail code: AST)

Time zones

• Atlantic Standard Time — UTC-4
• Alaska Standard Time — UTC-9
• Arabia Standard Time — UTC+3

Other uses

• Assured shorthold tenancy, a form of Assured tenancy with limited security of tenure
• Asturian language, a Romance language spoken in Asturias, Spain (ISO 639 alpha-3, ast)
• Arsenal Supporters' Trust, London, UK. Arsenal FC's critical friend of supporters and shareholders
• Athlitikos Syllogos Trikala 2000 BC, a top tier Greek basketball team
• Astana Team, the UCI code for the professional road bicycle racing team
• Anti Structure Tandem, a type of tandem-charge where the second charge can be delayed so that it explodes deep inside the structure