# CAS

/ˈkæs/ (US)

Source: https://englishreference.com/word/cas
Updated: 2026-08-08

## Senses

### 1. sports law

noun · CEFR B2 · Formal · Technical

Stands for Court of Arbitration for Sport.

For teachers: Abbreviation for Court of Arbitration for Sport. An international body established to settle disputes related to sport through arbitration.

- The athlete appealed the ban to the CAS in Switzerland.
- The CAS ruling provided a definitive resolution to the doping allegations that had overshadowed the international competition for months.

### 2. safety technology

noun · CEFR B2 · Technical

Stands for Collision Avoidance System.

For teachers: Abbreviation for Collision Avoidance System. A safety system designed to warn drivers or pilots of an imminent crash and, in some cases, take autonomous action.

- The new car model features a CAS that automatically applies the brakes.
- Modern commercial aircraft rely on a sophisticated CAS to maintain safe separation distances in crowded airspace.

### 3. military aviation

noun · CEFR C1 · Technical

Stands for Close Air Support.

For teachers: Abbreviation for Close Air Support. Tactical air action by aircraft against hostile targets that are in close proximity to friendly forces.

- The ground troops requested CAS to help them during the battle.
- Effective CAS requires precise coordination between ground controllers and pilots to avoid friendly fire incidents during high-intensity engagements.

### 4. chemistry database

noun · CEFR C1 · Technical

Stands for Chemical Abstracts Service.

For teachers: Abbreviation for Chemical Abstracts Service. A division of the American Chemical Society that maintains a comprehensive database of chemical substances.

- Every new chemical is assigned a unique CAS number.
- Researchers consulted the CAS registry to verify the properties of the newly synthesized compound before proceeding with the experiment.

### 5. mathematics software

noun · CEFR C1 · Technical

Stands for Computer Algebra System.

For teachers: Abbreviation for Computer Algebra System. A type of software program that allows for the manipulation of mathematical expressions in symbolic form.

- Students used a CAS to solve the complex equations.
- The integration of a CAS into the curriculum allowed students to focus on conceptual understanding rather than tedious manual calculations.

### 6. casual

adjective · CEFR B2 · Informal · Slang

a short way of saying 'casual', usually about clothes or a relaxed style.

For teachers: A clipped form of 'casual', typically used in informal registers to describe attire or social arrangements.

- The dress code for the party is smart cas.
- He showed up to the dinner in a cas outfit, looking much more relaxed than the other guests in their suits.

## Examples

- She checked her email on the CAS before boarding the flight.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.