(countable) A group, collection, category or set sharing characteristics or attributes.

(sociology, countable) A social grouping, based on job, wealth, etc. In Britain, society is commonly split into three main classes: upper class, middle class and working class.

(uncountable) The division of society into classes.

(uncountable) Admirable behavior; elegance.

(education, countable and uncountable) A group of students in a regularly scheduled meeting with a teacher.

A series of lessons covering a single subject.

(countable) A group of students who commenced or completed their education during a particular year. A school class.

(countable) A category of seats in an airplane, train or other means of mass transportation.

(taxonomy, countable) A rank in the classification of organisms, below phylum and above order; a taxon of that rank.

Best of its kind.

(statistics) A grouping of data values in an interval, often used for computation of a frequency distribution.

(set theory) A collection of sets definable by a shared property.

(military) A group of people subject to be conscripted in the same military draft, or more narrowly those persons actually conscripted in a particular draft.

(object-oriented programming, countable) A set of objects having the same behavior (but typically differing in state), or a template defining such a set in terms of its common properties, functions, etc.

One of the sections into which a Methodist church or congregation is divided, supervised by a class leader.

(transitive) To assign to a class; to classify.

(intransitive) To be grouped or classed.

(transitive) To divide into classes, as students; to form into, or place in, a class or classes.

(Ireland, Tyneside, slang) great; fabulous