source: アニメのフォント — 六畳間の侵略者！？ 勢力分布図 コメット, スーラ

an area of territory owned or controlled by a ruler or government:

(特に過去の)領地, 領土; 勢力範囲

e.g. the southwestern French domains of the Plantagenets.

a specified sphere of activity or knowledge:

(活動･関心･知識などの)分野, 領域, 範囲.

e.g. the expanding domain of psychology

e.g. figurative : visual communication is the domain of the graphic designer.

Physics a discrete region of magnetism in ferromagnetic material.

〘物理〙 磁区

Computing a distinct subset of the Internet with addresses sharing a common suffix or under the control of a particular organization or individual.

〘コンピュ〙 ドメイン〘ネットワークに接続されている組織などのグループ〙

Mathematics the set of possible values of the independent variable or variables of a function.

〘数〙 変域, 領域

late Middle English (denoting heritable or landed property): from French domaine, alteration (by association with Latin dominus ‘lord’) of Old French demeine ‘belonging to a lord’ (see demesne).