1. A department, such as a university department, a government department, or a department of a hospital.

2. A platoon. (military)

3. A class: a collection of sets defined by a common property. (mathematics)

4. class (a set of objects having the same behavior (but typically differing in state), or a template defining such a set in terms of its common properties, functions, etc) (object-oriented programming, countable)

5. A class: a taxonomic rank below phylum and above order, or a taxon at that level. (biology)

6. A coset: the set (and hence group) consisting of the results of the group operation applied to an element of a group and each element of one of its subgroups. (mathematics)

7. a hospital ward