demesnenoun [ C ]
/dɪˈmeɪn/old use an area of land owned and controlled by someone:
The Forest of Dean was the king's demesne.
old use the land belonging to a manor (= a large country house):
The enclosed fields of the manorial lord were known as the demesne.
literary part of a place or activity over which a person has control:
The garden is Alice's little demesne.