noun
one's innermost thoughts; one's true feelings
Literary and somewhat formal; used to express one's humble, sincere inner feelings, often in written or formal contexts.
微衷を述べる機会をいただき、感謝しております。
I am grateful for the opportunity to express my innermost thoughts.
彼の手紙には微衷がにじみ出ていた。
His letter revealed his true feelings.