noun
innermost feelings; heartfelt
Formal, often used in written expressions of gratitude, apology, or condolence. Common in phrases like 衷心より (heartfelt) or 衷心から (from the bottom of one's heart).
衷心よりお悔やみ申し上げます。
Please accept my heartfelt condolences.
ご支援に衷心から感謝いたします。
I express my heartfelt gratitude for your support.