What does the cryptic crossword clue "Acute loss at war for a hopeless ideal (4,5)" mean?

The wordplay uses an anagram. anagram of ACUTE + LOSS = LOSTCAUSE The answer is LOSTCAUSE.

Acute loss at war for a hopeless ideal (4,5)

Daily Mail Cryptic #17288 | 15 Down | 2024-02-07 flower