In the best of its category.

(agriculture) A commodity, usually produced on farms and part of a larger category. Products within a market class have similar physical characteristics, are grown or raised under similar conditions, and are bought and sold under similar terms and conditions.

(object-oriented programming) A nested inner class whose functions and member variables can be overridden and redefined by subclasses of an outer class. / (education) An online class.

(computational complexity theory) a set of computational problems of related resource-based complexity

(informal, derogatory, humorous) Economy class.

plural of class suit

Synonym of class action

(finance) A group of financial instruments that have similar financial characteristics and behave similarly in the marketplace.

(transitive, informal) To make more classy or sophisticated

A tuitional class held in the evening, typically for adults, and teaching a vocational or academic subject, practical skill, or recreational pursuit.