How to say "domain" in Japanese

• 領域りょういきJLPT N1approx.Common
  nounCovers 'domain' as an area or sphere — a region, or an abstract field of activity or knowledge. When 'domain' means a sphere rather than a state's land, this is the word you want.
  民間機みんかんきが軍事的ぐんじてき領域りょういきを侵犯しんぱんしたとのことです。↗

  A commercial airplane allegedly violated military airspace.
• 領土りょうどJLPT N1approx.Common
  noun'Domain' in the territorial sense: land under a nation's or ruler's control. Choose this when 'domain' means a country's territory; it does not serve for abstract domains like a field of study.
  あの島しまはアメリカの領土りょうどです。↗

  That island is American territory.
• 国土こくどJLPT N1approx.Common
  nounCovers 'domain' as a realm — the land of a country viewed as a whole. It fits when 'domain' means a nation's land itself, not an abstract sphere or someone's personal turf.
  アメリカは国土こくどが広ひろく、人々ひとびとはよく移動いどうする。↗

  America is a large country and its people are mobile.
• 領分りょうぶんCommon
  noun'Domain' as a sphere that is one's own — the share or province that belongs to someone. It suits talk of whose domain a matter is, rather than land held by a state.
  それは私の領分りょうぶんですよ。↗

  That's my province.
• 縄張りなわばりCommon
  nounCovers 'domain' as one's turf — a patch someone claims and guards. This is the word when 'domain' means someone's own ground in a territorial sense, not an abstract field of knowledge.

Use 領域 for a domain as an area or sphere, 領土 and 国土 for a country's territory or realm, 領分 for a sphere that is one's own, and 「縄張り」 for one's turf.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 領域りょういきterritory
• 領土りょうどterritory
• 国土こくどcountry
• 領分りょうぶんterritory
• ドメインdomain
• 変域へんいきdomain (of a function)
• 定義域ていぎいきdomain (of a function)
• 始域しいきdomain (of a function)
• 所有地しょゆうちone's land
• 領野りょうやarea
• 縄張りなわばりone's turf