Noun

(categories)

A group, often named or numbered, to which items are assigned based on similarity or defined criteria.

*

The traditional way of describing the similarities and differences between constituents is to say that they belong to categories'' of various types. Thus, words like ''boy'', ''girl'', ''man'', ''woman'', etc. are traditionally said to belong to the category''' of Nouns, whereas words like ''a'', ''the'', ''this'', and ''that'' are traditionally said to belong to the ' category of Determiners.

This steep and dangerous climb belongs to the most difficult category .

I wouldn't put this book in the same category as the author's first novel.

(mathematics) A collection of objects, together with a transitively closed collection of composable arrows between them, such that every object has an identity arrow, and such that arrow composition is associative.

One well-known category has sets as objects and functions as arrows.

Just as a monoid consists of an underlying set with a binary operation "on top of it" which is closed, associative and with an identity, a category consists of an underlying digraph with an arrow composition operation "on top of it" which is transitively closed, associative, and with an identity at each object. In fact, a category's composition operation, when restricted to a single one of its objects, turns that object's set of arrows (which would all be loops) into a monoid.

Noun

(series)

A number of things that follow on one after the other or are connected one after the other.

* {{quote-book, year=1963, author=(Margery Allingham), title=(The China Governess)

, chapter=19 citation , passage=When Timothy and Julia hurried up the staircase to the bedroom floor, where a considerable commotion was taking place, Tim took Barry Leach with him. […]. The captive made no resistance and came not only quietly but in a series of eager little rushes like a timid dog on a choke chain.}}

* {{quote-magazine, date=2013-06-28, author=(Joris Luyendijk)

, volume=189, issue=3, page=21, magazine=(The Guardian Weekly) , title= Our banks are out of control , passage=Seeing the British establishment struggle with the financial sector is like watching an alcoholic […].  Until 2008 there was denial over what finance had become. When a series of bank failures made this impossible, there was widespread anger, leading to the public humiliation of symbolic figures.}}

(US, Canada) A television or radio program which consists of several episodes that are broadcast in regular intervals

Friends was one of the most successful television series in recent years.

(British) A group of episodes of a television or radio program broadcast in regular intervals with a long break between each group, usually with one year between the beginning of each.

(mathematics) The sum of the terms of a sequence.

(cricket, baseball) A group of matches between two sides, with the aim being to win more matches than the opposition.

(zoology) An unranked taxon.

(senseid) A subdivision of a genus, a taxonomic rank below that of section (and subsection) but above that of species.