domain

noun

1. a particular environment or walk of life

   noun.state

   Synonyms area arena field orbit sphere

   Source: WordNet 3.0

2. territory over which rule or control is exercised

   noun.location

   Examples

   His domain extended into Europe.

   Synonyms demesne land

   Source: WordNet 3.0

3. (mathematics) the set of values of the independent variable for which a function is defined

   noun.group

   Synonyms domain of a function

   Source: WordNet 3.0

4. people in general; especially a distinctive group of people with some shared interest

   noun.group

   Synonyms world

   Source: WordNet 3.0

5. the content of a particular field of knowledge

   noun.cognition

   Synonyms knowledge base knowledge domain

   Source: WordNet 3.0

6. Dominion; empire; authority.

   noun

   Source: webster1913