The most common and most likely answer to this crossword clue is the 9 letter word KIDNAPPER
I've seen this crossword clue in The Guardian
K
I
D
N
A
P
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R
More clues leading to the result KIDNAPPER
- Child meeting the head, one guilty of serious wrongdoing?
- One may take issue with rising fish stocks
- One having taken another fish, also hooked up
- Criminal‘s basic characteristics seen in Leave voter
- Criminal joke, one having a lie down?
- Pied Piper type, in make-up, wearing oversized tie
- Child sent to head as a serious offender
- One captures Farage fan getting in with revolutionary
- Tease your Head – he might lock you away!
- One snatching another fish and eaten up
Buddy explains!

The straight part
We know that "One having taken another" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one having taken another = kidnapper.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 KIDNAPPER mean?
KIDNAPPER noun- A person who kidnaps someone.