領域|りょういきryouiki[0]heiban (flat)

1. nounterritory; domain
   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.
2. nounfield; area; domain; sphere; realm
   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.
3. noun, mathdomain; region

• Synonym領分りょうぶんNeutralOne's own sphere of influence or one's proper concern; 「領域」 is the more formal term.
• Synonym国土こくどNeutralA country's land as its territory; 「領域」 also takes in territorial waters and airspace.
• Synonym領地りょうちNeutralThe lands held by a feudal lord; 「領域」 is the broader, more general word.
• SynonymエリアNeutralA loanword for an area or zone, at home in commerce, transport, disaster prevention and the like; 「領域」 leans academic or territorial.
• SynonymゾーンNeutralA loanword for a zone or belt, as in 「ストライクゾーン」.
• SynonymフィールドNeutralA loanword for a field of specialization or the open field, as in 「フィールドワーク」.
• Synonym区域くいきNeutralA zone with boundaries drawn around it; 「領域」 leans toward academic fields or territory.
• Synonym地域ちいきNeutralA region or local community; 「領域」 leans toward academic fields or territory.
• Synonym地区ちくNeutralA particular district, as in 「被災地区」 or 「山間地区」, including administrative districts; 「領域」 leans academic or territorial.
• Synonym範囲はんいNeutralScope or extent, how far something reaches; 「領域」 is about the domain under one's control.
• Synonym分野ぶんやNeutralA field of study or work, as in 「専門分野」; close to 「領域」, and common in both speech and writing.
• Related地帯ちたいNeutralA belt or zone with a character of its own, as in 「工業地帯」 or 「危険地帯」; 「領域」 centers on territory or academic fields.
• Related方面ほうめんNeutralCovers a district lying in a certain direction, and also fields or aspects; 「領域」 is the more formal choice.
• Related世界せかいNeutralMetaphorically the circle around a trade or pursuit, as in 「芸能の世界」; 「領域」 leans academic.
• Related部門ぶもんNeutralA division of an organization or a class of entrants in a contest; 「領域」 is about academic fields or territory.
• Related限度げんどNeutralA limit or bound that must not be crossed; 「領域」 is about the scope under one's control.
• Related限りかぎりNeutral「限り」 marks an end or limit, the point where something stops; 「領域」 is about the scope under one's control.
• Related域いきWrittenA written-style word, mostly a suffix for a range or level, as in 「専門の域」; 「領域」 is the full standalone word.

Use 「領域」 for a nation's territory, waters and airspace included, or for an academic domain. For a field of study or work pick 「分野」; for a geographic area 「地域」 or 「地区」; for a demarcated or commercial zone 「エリア」; for a belt with a shared character 「地帯」; for scope or extent 「範囲」; for one's own sphere of influence 「領分」. 「方面」 covers directions and aspects, 「部門」 organizational divisions, 「世界」 a trade's circle, and the loanwords 「ゾーン」 and 「フィールド」 for zones and fields of work.

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

1. 領地りょうちの区域くいき。
2. 関係かんけいの及およぶ範囲はんい。
3. 有限ゆうげん次元じげんベクトル空間くうかんの開かい部分ぶぶん集合しゅうごうで連結れんけつなもの。