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.
He devoted himself single-mindedly to his research.
Their wholehearted efforts bore fruit.
Also means single-minded concentration, but often emphasizes an absorbed state without distraction, while 専心一意 stresses wholehearted dedication to a goal.
A near-synonym with the same kanji in reverse order; essentially interchangeable, though 専心一意 is slightly more common.
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.