The most common and most likely answer to this crossword clue is the 10 letter word STRONGHOLD
I've seen this crossword clue in The Guardian
S
T
R
O
N
G
H
O
L
D
More clues leading to the result STRONGHOLD
- Keep firm grasp in wrestling?
- Keep firm grasp in wrestling
- Keep firm and carry on
- Wretched ghost beginning to nettle Lord Nelson, maybe
- Keep stiff and carry on
- ‘Is it wrong chopping heads off?’
- Keep provoking Hardy and Nelson?
- Keep a firm grip
- Fort betrayed as throng poured in
- A powerful grip, useful in defence
Buddy explains!
The straight part
We know that "castle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case castle = stronghold.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 STRONGHOLD mean?
STRONGHOLD noun- A place built to withstand attack; a fortress.
- A place of domination by, or refuge or survival of, a particular group or idea.