How to say "realm" in Japanese

• 分野ぶんやJLPT N3approx.Common
  nounCovers 'realm' in the abstract sense of a field or branch of study, work, or activity — the natural choice for 'the realm of science' or 'a new realm of inquiry.'
  彼かれはこの分野ぶんやでは草分くさわけだ。↗

  He is a trailblazer in this field.
• 国土こくどJLPT N1approx.Common
  nounMatches 'realm' in its concrete territorial sense: the land of a country or the territory ruled over by a sovereign. It denotes the land itself, not an abstract sphere.
  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.
• 天地てんちJLPT N1approx.Common
  nounLiterally 'heaven and earth': the world or land as a whole. It suits the grand sense of 'realm' — the whole world — rather than a branch of study or a territory.
• 領域りょういきJLPT N1approx.Common
  nounCovers 'realm' as a domain or sphere with a sense of extent — a research domain, the realm of possibility. It ranges wider than 分野, taking in physical areas as well as abstract fields.
  かかわってくる問題もんだいは経済学けいざいがくの領域りょういきをはるかに越こえている。↗

  The questions involved go far beyond economics.
• 場ばJLPT N3approx.Common
  nounEssentially a place or setting — the scene or venue of an activity. As 'realm' it fits only the sense of an arena or sphere of activity, so it is seldom the word you want.

Use 分野 for a field of study or activity, 領域 for a domain or zone, 国土 for a nation's territory, 天地 for the world as a whole, and 場 only for the setting of an activity.

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

• 分野ぶんやfield
• 国土こくどcountry
• 邦土ほうどrealm
• 天地てんちland
• 領域りょういきfield
• 場ばfield