one mind; wholeheartedness; single-hearted devotion
Refers to a state of being of one mind, wholeheartedly devoted to something, or acting with complete sincerity and unity of purpose. Often used in contexts of dedication, prayer, or collective resolve.
He devoted himself wholeheartedly to his research.
Everyone came together as one to support the disaster area.
Standard kanji-kana mixed spelling.
Kana spelling for the numeral part; less common but still encountered.
Compound of 一つ (ひとつ, 'one') and 心 (こころ, 'heart, mind'). The exact historical derivation is uncertain, but the word literally means 'one heart/mind' and has been used to express unity of purpose or wholeheartedness.