The most common and most likely answer to this crossword clue is the 9 letter word OUTERMOST
I've seen this crossword clue in The Daily Telegraph
O
U
T
E
R
M
O
S
T
More clues leading to the result OUTERMOST
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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 OUTERMOST mean?
OUTERMOST adjective- Outside; external.
- Farther from the centre of the inside.
- That which is outermost; the surface; the outside.