Meaning of DOMAIN in English
do ‧ main AC /dəˈmeɪn, dəʊ- $ də-, doʊ-/ BrE AmE noun [countable] formal
[ Date: 1400-1500 ; Language: French ; Origin: domaine , from Latin dominus 'lord' ]
1 . an area of activity, interest, or knowledge, especially one that a particular person, organization etc deals with
outside/within the domain of something/somebody
This problem is outside the domain of medical science.
Looking after the house was viewed as a woman’s domain.
⇨ ↑ public domain
2 . an area of land owned and controlled by one person or government, especially in the past:
the extent of the royal domain
3 . technical the set of possible quantities by which something can vary in mathematics
4 . a domain name
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012