Webster 1913 Edition



, Gr. [GREEK], fr. [GREEK] to accuse, affirm, predicate; [GREEK] down, against + [GREEK] to harrangue, assert, fr. [GREEK] assembly.]
One of the highest classes to which the objects of knowledge or thought can be reduced, and by which they can be arranged in a system; an ultimate or undecomposable conception; a predicament.
or predicaments – the former a Greek word, the latter its literal translation in the Latin language – were intended by Aristotle and his followers as an enumeration of all things capable of being named; an enumeration by the
summa genera
i.e., the most extensive classes into which things could be distributed.
J. S. Mill.
Class; also, state, condition, or predicament;
as, we are both in the same
There is in modern literature a whole class of writers standing within the same
De Quincey.

Webster 1828 Edition



In logic, a series or order of all the predicates or attributes contained under a genus. The school philosophers distributed all the objects of our thoughts and ideas into genera or classes. Aristotle made ten categories,
Substance, quantity, quality, relation, action, passion, time, place, situation and habit.

Definition 2022



For information about Wiktionary categories, see Wiktionary:Categorization.



category (plural categories)

  1. A group, often named or numbered, to which items are assigned based on similarity or defined criteria.
    • 1988, Andrew Radford, Transformational grammar: a first course, Cambridge, UK: Cambridge University Press, ISBN 0-521-34750-5, page 51:
      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.
  2. (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.



Derived terms

Related terms

Related terms


External links

  • category in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
  • category in The Century Dictionary, The Century Co., New York, 1911