A somewhat formal or literary noun expressing utmost sincerity and wholehearted devotion. Often used in serious contexts such as moral philosophy, speeches, or written expressions of commitment.
Everyone was moved by his words filled with utmost sincerity.
If you approach matters with complete sincerity, a path will surely open.
A Sino-Japanese compound of 至 (utmost) and 誠 (sincerity), literally meaning 'utmost sincerity'. The exact historical derivation is uncertain, but the word has been used in classical Chinese and Japanese texts to denote the highest degree of sincerity and devotion.