Must-have (adjective)

1. Something that is essential or necessary.
2. Something that is highly desirable or sought after.

Origin:

A colloquial term, used to indicate that something is essential or necessary.

Examples:

1. The new iPhone is a must-have for tech enthusiasts.
2. A good pair of hiking boots is a must-have for any serious hiker.
3. This new book is a must-have for fans of the series.
4. The little black dress is a must-have in any woman's wardrobe.
5. The must-have accessory for this season is a oversized scarf.