extreme regret; height of bitterness
A strong, often formal expression for deep regret or chagrin, typically used in serious contexts such as apologies, sports commentary, or news reports.
Losing the match is a matter of extreme regret.
He looked back on his mistake with an expression of the deepest chagrin.
残念 is a common, everyday word for 'regrettable' or 'disappointing'; 痛恨の極み is much stronger and more formal, used for profound personal or professional regret.
Standard kanji spelling for this fixed expression.
Mixed kanji-kana spelling; 極み is sometimes written in kana for readability.
Compound of 痛恨 (deep regret) + の (possessive particle) + 極み (extreme, height). The phrase follows a classical pattern for expressing the utmost degree of a feeling.