noun
Refers to a sphere of activity, knowledge, or influence; somewhat formal and often used in academic or abstract contexts.
彼の研究は新しい領野を切り開いた。
His research opened up a new field.
この問題は私の専門領野を超えている。
This problem is beyond my area of expertise.
Compound of 領 (りょう, 'territory, domain') and 野 (や, 'field, plain'). The exact historical derivation is uncertain, but the combination conveys a bounded area of activity or knowledge.