/ˈkætəˌɡɔɹi/► audioScrabble 14Words With Friends 15
Definition
noun a collection of things sharing a common attribute.
— synonyms: class, family
noun a general concept that marks divisions or coordinations in a conceptual scheme.
Examples
“I wouldn't put this book in the same category as the author's first novel.”
“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.”