The most common and most likely answer to this crossword clue is the 7 letter word RIPCORD
I've seen this crossword clue in The Times
R
I
P
C
O
R
D
Buddy explains!
The straight part
We know that "Without the use of which one might drop dead?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case without the use of which one might drop dead? = ripcord.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 RIPCORD mean?
RIPCORD noun- A cord to release a parachute from its sack.