noun, adverb
single-mindedly; wholeheartedly; with heart and soul
A yojijukugo used to describe devoting oneself entirely to a single purpose, often with strong emotional commitment. Can function as a noun or adverbially with に.
彼は専心一意に研究に打ち込んだ。
He devoted himself single-mindedly to his research.
専心一意の努力が実を結んだ。
Their wholehearted efforts bore fruit.
A yojijukugo composed of 専心 (wholehearted devotion) and 一意 (single-mindedness). The exact historical origin is uncertain, but it follows a common four-character pattern for expressing focused dedication.