The most common and most likely answer to this crossword clue is the 8 letter word CELLMATE
I've seen this crossword clue in Independent
C
E
L
L
M
A
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E
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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 CELLMATE mean?
CELLMATE noun- A person with whom one shares a prison cell.