Cryptic crossword clue
Crook nabs Bill King, becomes stern 4,3

The most common and most likely answer to this crossword clue is the 4 plus 3 letter word BACK END

B
A
C
K
E
N
D

Buddy explains!

The straight part
We know that "stern" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stern = back end.
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 BACK END mean?

BACK END noun
  1. The rear, back, or unseen portion (of something).
  2. That part of a hardware or software system that is farthest from the user; the internals rather than the user interface.
  3. The latter end of any given time, especially the latter part of the year; autumn; late autumn.
BACK END adjective
  1. Relating to the back end part of a hardware or software system.

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