expression, adverb
after efforts in vain; all efforts having been in vain
Used adverbially to indicate that despite one's efforts, the result was futile or unsuccessful. Often appears at the beginning of a sentence or clause.
努力も虚しく、彼は試験に落ちてしまった。
After all his efforts in vain, he failed the exam.
努力も虚しく、プロジェクトは中止になった。
Despite their efforts, the project was canceled.
Similar meaning but more explicitly states that the effort yielded no reward. 努力も虚しく emphasizes the emptiness or futility of the effort itself.
A set phrase composed of 努力 (effort) + も (even) + 虚しく (adverbial form of 虚しい, meaning 'empty' or 'futile'). The expression is a fixed adverbial phrase.