What does the cryptic crossword clue "Prove ineffective, as would Shackleton's Endurance ultimately? (3,2,3)" mean?

The definition is "Prove ineffective". The wordplay uses a double definition. Double definition The answer is CUT NO ICE.

Prove ineffective, as would Shackleton's Endurance ultimately? (3,2,3)

Times Cryptic #29212 | 5 Across | 2025-04-24 flower