General term for a sphere of activity, knowledge, or control. Used in both technical and everyday contexts.
I acquired a domain for the new website.
His domain of expertise is artificial intelligence.
This problem is outside my domain.
I registered a domain under the company name.
I forgot to renew it, and the domain expired.
I renew the domain every year.
domain name
subdomain
adjacent domain
top-domain
domain name
account domain
public domain
top-level domain; TLD
Borrowed from English 'domain'. The internet sense is a shortening of ドメイン名 (domain name).