| category | |
| 1. n. 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. | |
| 2. n. (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 i | |
| 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 arr | |
