territorialist
/ˌtɛrɪˈtɔriəlɪst/
noun
- A person who strongly defends or claims control over a particular area or domain.
- As a territorialist, he refused to let anyone use his parking spot.
- The cat was a real territorialist, hissing at any other animal that entered the garden.
- In the debate, she was a territorialist about her department's budget.