category
Definition from Wiktionary, the free dictionary
- For information about Wiktionary categories, see Wiktionary:Categorization.
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English [edit]
Etymology [edit]
From Middle French categorie, from Late Latin categoria (“class of predicables”), from Ancient Greek κατηγορία (kategoria, “head of predicables”).
Pronunciation [edit]
Noun [edit]
category (plural categories)
- A group, often named or numbered, to which items are assigned based on similarity or defined criteria.
- 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.
Synonyms [edit]
- (group to which items are assigned): class, family, genus, group, kingdom, order, phylum, race, tribe, type
- See also Wikisaurus:class
Derived terms [edit]
Terms derived from "category"
Related terms [edit]
Terms etymologically related to "category"
Translations [edit]
group
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collection in math
- The translations below need to be checked and inserted above into the appropriate translation tables, removing any numbers. Numbers do not necessarily match those in definitions. See instructions at Help:How to check translations.
External links [edit]
- category in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
- category in The Century Dictionary, The Century Co., New York, 1911
