domain

noun

• 1an area of territory owned or controlled by a particular ruler or government:the French domains of the Plantagenets
• a specified sphere of activity or knowledge:the country’s isolation in the domain of sport

• 2 Computing a distinct subset of the Internet with addresses sharing a common suffix or under the control of a particular organization or individual.

• 3 Physics a discrete region of magnetism in ferromagnetic material.

• 4 Mathematics the set of possible values of the independent variable or variables of a function.

• 5 Biochemistry a distinct region of a complex molecule or structure.