- anything under a person's complete control or authority
- The estate or domain of a feudal lord.
- An organization or department over which one dominant person or group exercises control.
- The estate controlled by a feudal lord; a fief.
- The duke's fiefdom had been greatly expanded as a reward for his dutiful military service on behalf of the king.
- (by extension, chiefly pejorative) Any organization in the control of a dominant individual.
- 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.