# ast

/ˈæst/ (US) · CEFR C2 · Noun

Source: https://englishreference.com/word/ast
Updated: 2026-07-22

## Definition

Stands for Aspartate Aminotransferase. A protein found in your liver and heart that doctors measure to check if these organs are healthy. In computing, an AST is a tree-like map that shows the structure of computer code so a program can understand and process it.

For teachers: Abbreviation for Aspartate Aminotransferase. An enzyme found primarily in the liver, heart, and skeletal muscles that is released into the bloodstream when these tissues are damaged. In computer science, an Abstract Syntax Tree (AST) is a tree representation of the abstract syntactic structure of source code written in a programming language.

## Examples

- The doctor ordered a blood test to check my AST levels.
- High levels of AST in the blood can indicate liver damage or a recent heart attack.
- While AST is a sensitive marker for hepatic injury, clinicians often compare it with ALT levels to determine the specific cause of organ dysfunction.

## Usage notes

- Typically used as an uncountable noun in medical contexts; often appears in the phrase 'AST levels'.

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