A more thorough explanation:

An adjunct is something that is added to another thing as an extra or temporary part. It is usually attached in a subordinate or secondary role.

Examples:

• An adjunct professor is a teacher who is hired on a temporary or part-time basis, usually to teach a specific course or subject.
• A GPS system is an adjunct to a car, providing additional information and guidance to the driver.
• A salad dressing is an adjunct to a salad, adding flavor and texture to the vegetables.

These examples illustrate how an adjunct is something that is added to another thing to enhance or supplement it, but is not an essential or permanent part of it.