The most common and most likely answer to this crossword clue is the 11 letter word ELIMINATION
I've seen this crossword clue in The Sunday Telegraph
E
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More clues leading to the result ELIMINATION
Buddy explains!
The straight part
We know that "Killing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case killing = elimination.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 ELIMINATION mean?
ELIMINATION noun- The act of eliminating, expelling or throwing off.
- The act of excluding a losing contestant from a match, tournament, or other competition.
- The act of voting off or throwing off a contestant in a reality television competition.
- The act of discharging or excreting waste products or foreign substances through the various emunctories.
- The act of causing a quantity to disappear from an equation; especially, in the operation of deducing from several equations containing several unknown quantities a less number of equations containing a less number of unknown quantities.
- The act of obtaining by separation, or as the result of eliminating; deduction.
- The act of recording amounts in a consolidation statement to remove the effects of inter-company transactions.