# PAC

/ˈpæk/ (US)

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

## Senses

### 1. political fundraising group

noun · CEFR C1 · American English · Technical

Stands for Political Action Committee. In the US, this is an organization that collects money from members to support or oppose political candidates.

For teachers: Abbreviation for Political Action Committee. An organization in the United States that pools campaign contributions from members and donates those funds to campaigns for or against candidates, ballot initiatives, or legislation.

- The candidate received a large donation from a PAC representing the local teachers' union.
- The influence of corporate PACs on federal elections remains a central point of contention in debates regarding campaign finance reform.

### 2. industrial computer controller

noun · CEFR C2 · Technical

Stands for Programmable Automation Controller. It is a type of computer used in factories to control machines and robots.

For teachers: Abbreviation for Programmable Automation Controller. A digital computer used for automation of typically industrial electromechanical processes, combining the features of a PLC with the processing power of a PC.

- The engineer installed a new PAC to manage the assembly line more efficiently.
- Modern manufacturing facilities often prefer a PAC over a traditional PLC when the system requires complex motion control and high-speed data processing.

### 3. web browser configuration file

noun · CEFR C2 · Technical

Stands for Proxy Auto-Config. It is a file that tells your web browser how to connect to the internet through a proxy server.

For teachers: Abbreviation for Proxy Auto-Config. A file format used by web browsers to determine whether web traffic should go directly to the destination or be routed through a proxy server.

- The IT department updated the PAC file to fix the connection issues in the office.
- By deploying a centralized PAC file, the network administrator can dynamically manage how different browsers within the organization handle external traffic.

### 5. machine learning theory

adjective · CEFR C2 · Academic · Technical

Stands for Probably Approximately Correct. It is a way to describe how well a computer program learns from data.

For teachers: Abbreviation for Probably Approximately Correct. A mathematical framework for analyzing machine learning algorithms to determine the number of samples needed to learn a hypothesis with high probability and low error.

- The professor explained the PAC learning model in the advanced computer science class.
- The PAC framework provides a rigorous theoretical basis for understanding the generalization capabilities of various supervised learning algorithms.

## Examples

- The PAC raised millions of dollars for the election.
- Several large corporations donated to the PAC to ensure their interests were represented in the upcoming environmental bill.
- While individual contributions are strictly capped, a PAC allows like-minded donors to pool their resources, thereby exerting a more significant influence on the legislative process through targeted campaign spending.

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