noun, noun or participle which takes 'suru', intransitive verb
being indifferent; having no concern
Dated literary expression meaning complete indifference or lack of relation, often used in the set phrase 風馬牛不相及 (even horses and cattle in heat do not come near each other). Rare in modern Japanese outside classical or literary contexts.
「風馬牛」は、互いに無関係で無関心なことを表す古い表現だ。
風馬牛 is an old expression meaning that things are unrelated and indifferent to each other.