1. the domain controlled by a feudal lord

Definition categories: location, demesne, domain, land

2. an organization that is controlled by a dominant person or group

Definition categories: group, organisation, organization

Sentences with fiefdom as a noun:

- The duke's fiefdom had been greatly expanded as a reward for his dutiful military service on behalf of the king.

- Most of our company's computers are standardized, but the IT director allows the employees in his own little fiefdom to specify their own machines.