The most common and most likely answer to this crossword clue is the 9 letter word STEADIEST
I've seen this crossword clue in Financial Times
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More clues leading to the result STEADIEST
Buddy explains!
The straight part
We know that "Most secure" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case most secure = steadiest.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 STEADIEST mean?
STEADIEST adjective- Firm in standing or position; not tottering or shaking; fixed; firm.
- Constant in feeling, purpose, or pursuit; not fickle, changeable, or wavering; not easily moved or persuaded to alter a purpose; resolute.
- Smooth and not bumpy or with obstructions.
- Regular and even.
- Slow.