The most common and most likely answer to this crossword clue is the 9 letter word DO-OR-DIE
I've seen this crossword clue in The Times
D
O
-
O
R
-
D
I
E
More clues leading to the result DO-OR-DIE
- After entrance, fail to make final desperate effort
- Desperate entrance and exit
- Risky opening with backgammon piece
- In Berlin, the following entrance is risky
- 1 Risky opening with backgammon piece
- Desperate one that is going after retreating Dickens character
- A choice, but, is it really one?
- Motivating slogan at entrance and exit?
Buddy explains!

The straight part
We know that "final desperate effort" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case final desperate effort = do-or-die.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DO-OR-DIE mean?
DO-OR-DIE adjective- Requiring a determined or desperate effort to avoid the consequences of failure.