プログレッシブ和英中辞典(第4版)の解説
せっかく【折角】
❶〔骨を折って，わざわざ〕
母がせっかく作ったご馳走がテーブルの上で冷たくなっている
The dinner my mother prepared so carefully is getting cold on the table.
せっかく訪ねてくれたのに私はあいにく留守だった
He had come all the way to see me but unfortunately I was out.
彼の失敗でせっかくの苦心も水の泡だ
All our efforts came to nothing because of his blunder.
❷〔相手の努力を謝して〕
せっかくのご招待ですから喜んで伺います
How kind of you to ask me! I'd love to come.
せっかくですが，今回はお伴できません
Thank you (very much), but I'm afraid I can't come with you this time.
❸〔たまにしかないこと〕せっかくの rare；〔たまにしかなくて貴重な〕valuable
せっかくの機会だったのに
You should have taken advantage of such a rare opportunity.
せっかくの日曜日が彼のために駄目になってしまった
Because of him, the Sunday we had so looked forward to was ruined.
雨でせっかくの晴れ着が台無しだ
The rain spoiled her best clothes, which she had put on especially for the occasion.
❹〔気を付けて〕
折角ご自愛下さい
Please take good care of yourself.