domain Definition

1. The scope of any subject or area of interest.

Thesaurus: work, discipline, area, field, forte, province, sphere, realm, realty, job, branch, department.
2. A territory owned or ruled by one person or government.

Thesaurus: property, real estate, land, empire, scope, realm, region, territory.
3. math.
The set of values specified for a given mathematical function.
4. physics.
In a ferromagnetic substance, eg iron or nickel: a small region within which individual magnetic moments (see moment sense 5) can be aligned, giving that substance permanent magnetic properties.
(Austral)
(NZ)
5. A public park or recreation area.