noun, noun which may take the genitive case particle 'no'
deep regret; bitter grief
Expresses profound regret or sorrow, often over a serious mistake, loss, or failure. Common in formal, literary, or news contexts.
彼は痛恨のミスで試合に負けた。
He lost the match due to a deeply regrettable mistake.
社長は不正会
The president expressed deep regret over the accounting fraud.