Definition of "class"

class

/klɑːs/

noun
countable and uncountable, plural classes
1. (countable) A group, collection, category or set sharing characteristics or attributes.
  Quotations
  The Magpies are unbeaten and enjoying their best run since 1994, although few would have thought the class of 2011 would come close to emulating their ancestors.
  2011 October 1, Saj Chowdhury, “Wolverhampton 1-2 Newcastle”, in BBC Sport
2. (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.
  Quotations
  Seeing the British establishment struggle with the financial sector is like watching an alcoholic […]. Until 2008 there was denial over what finance had become. […] But the scandals kept coming, and so we entered stage three – what therapists call "bargaining". A broad section of the political class now recognises the need for change but remains unable to see the necessity of a fundamental overhaul. Instead it offers fixes and patches.
  2013 June 28, Joris Luyendijk, “Our banks are out of control”, in The Guardian Weekly, volume 189, number 3, page 21
3. (uncountable) The division of society into classes.
4. (uncountable) Admirable behavior; elegance.
5. (education, countable and uncountable) A group of students in a regularly scheduled meeting with a teacher.
6. A series of lessons covering a single subject.
7. (countable) A group of students who commenced or completed their education during a particular year. A school class.
8. (countable) A category of seats in an airplane, train or other means of mass transportation.
  Quotations
  The City & South London was also the first British passenger railway to offer only one class.
  2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, page 101
9. (taxonomy, countable) A rank in the classification of organisms, below phylum and above order; a taxon of that rank.
10. Best of its kind.
  Quotations
  The mark made by Cory a new Central A. U. mark and he appears to be the class of the field in this event.
  1913 June 27, “The Crime Is Not in Making a Mistake, but in Repeating It.”, in Chicago Tribune
  University of Southern California's 7 to 0 defeat of the mighty Cardinal team ranked the victors the class of the far west
  1929 October 27, “89,000 Watch So. California Defeat Stanford, 7 to 0”, in Chicago Tribune
  Roosevelt (14-1) looked very much like the class of the OIA.
  2009 May 8, “Waianae forces OIA rematch”, in Honolulu Star-Bulletin
11. (statistics) A grouping of data values in an interval, often used for computation of a frequency distribution.
12. (set theory) A collection of sets definable by a shared property.
  Quotations
  In the present section we shall discuss the various systems of set theory which admit, beside sets, also classes. Classes are like sets, except that they can be very comprehensive; an extreme example of a class is the class which contains all sets. […] The main point which will, in our opinion, emerge from this analysis is that set theory with classes and set theory with sets only are not two separate theories; they are, essentially, different formulations of the same underlying theory.
  1973, Abraham Fraenkel, Yehoshua Bar-Hillel, Azriel Lévy, Foundations of Set Theory, 2nd edition, Elsevier, page 119
13. (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.
14. (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.
15. One of the sections into which a Methodist church or congregation is divided, supervised by a class leader.
verb
third-person singular simple present classes, present participle classing, simple past and past participle classed
1. (transitive) To assign to a class; to classify.
  Quotations
  She was a fat, round little woman, richly apparelled in velvet and lace, […]; and the way she laughed, cackling like a hen, the way she talked to the waiters and the maid, […]—all these unexpected phenomena impelled one to hysterical mirth, and made one class her with such immortally ludicrous types as Ally Sloper, the Widow Twankey, or Miss Moucher.
  1918, W. B. Maxwell, chapter 2, in The Mirror and the Lamp‎
2. (intransitive) To be grouped or classed.
  Quotations
  the genus or family under which it classes
  1790, Edward Tatham, The Chart and Scale of Truth
3. (transitive) To divide into classes, as students; to form into, or place in, a class or classes.
adjective
not comparable
1. (Ireland, Tyneside, slang) great; fabulous
  Quotations
  To talented authors Tim Ash and Brian Reich for introducing me to John Wiley & Sons—a truly class outfit.
  2009, Erik Qualman, Socialnomics