overarching

John J. Rateyの "SPARK" を読んでいます。
The overarching principle of the fight-or-flight response is marshaling resouces for immediate needs in lieu of building for the future--act now, ask questions later. The hormonal rush of epinephrine focuses the body, increasing heart rate and blood pressure and dilating the bronchial tubes of the lungs to carry more oxygen to the muscles.

"overarching" の意味を辞書で調べます。

・Oxford English Dictionary: Comprehensive; all-embracing.: ‘a single overarching principle’

・Collins Dictionary: You use overarching to indicate that you are talking about something that includes or affects everything or everyone.[formal]: The overarching question seems to be what happens when the U.S. pulls out?
・Cambridge English Dictionary: most important, because of including or affecting all other areas: The overarching theme of the election campaign was tax cuts.

意味や辞書の備考に[formal]とある点からすると今までに何度か見たことがあっても当然な単語ですが、初めて見る単語の気がします。