Translation guide
The English word 'domain' covers several distinct concepts. This guide helps learners choose the right Japanese expression based on the intended meaning, from fields of expertise to internet domains and territories.
Referring to an area of knowledge, study, or professional activity.
The most common and versatile word for 'field' or 'domain' in academic, professional, or general contexts.
His domain of expertise is physics.
Often used for 'domain' in the sense of a defined area of knowledge or activity, slightly more formal than 分野. Can also mean 'territory' or 'zone'.
Means 'scope' or 'range'. Used when 'domain' refers to the extent of something, such as responsibilities or coverage.
Referring to a domain name on the internet (e.g., example.com).
Referring to a physical territory, land, or area under control.
Specifically means 'territory' or 'dominion' in a political or geographical sense.
Referring to a non-physical realm, such as the domain of dreams, the public domain, etc.
Literally 'world', often used to mean 'domain' in a figurative sense, like 'the world of art'.
The set of input values for which a function is defined.
Both can mean 'field' or 'domain'. 分野 is more common for academic or professional fields. 領域 can sound more formal or refer to a bounded area, including physical territory or abstract realms.
His research domain is biology.
Research in this domain is advancing rapidly.
それは私の専門領域外です。
That is outside my domain of expertise.
This issue is beyond my domain of responsibility.
The direct loanword for internet domain. Universally understood in tech contexts.
I registered a new domain.
That site's domain ends with '.jp'.
That country has a vast domain.
Historical term for a feudal domain or fief. Used in contexts like samurai territories.
In the Edo period, feudal lords governed their domains.
Means 'territory' in the sense of a gang's turf or an animal's territory. Informal and specific.
That park is their domain.
That's a story from the domain of dreams.
Also used for abstract domains, like 'the domain of science'.
That transcends the domain of science.
The standard mathematical term for 'domain' of a function.
The domain of this function is all real numbers.
それは私の専門領域ではありません。
That is not my area of expertise.
The loanword ドメイン is almost exclusively used for internet domains. Using it for 'field of expertise' or 'territory' will sound unnatural.
The domain of science is vast.