The most common and most likely answer to this crossword clue is the 8 letter word SECLUDED
I've seen this crossword clue in The Daily Telegraph
S
E
C
L
U
D
E
D
More clues leading to the result SECLUDED
- Private Harry cuddles without energy
- On return, deduces pounds must go inside, hidden
- Quiet son banned from school, having denied Cross
- Private society avoided getting caught inside
- Out-of-the-way tipsy cuddles, ecstasy to be hugged
- Secret society avoided getting caught inside
- Private Society avoided admitting Conservative
Buddy explains!

The straight part
We know that "Secret" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case secret = secluded.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 SECLUDED mean?
SECLUDED verb- To shut off or keep apart, as from company, society, etc.; withdraw (oneself) from society or into solitude.
- To shut or keep out; exclude; preclude.
- Hidden, isolated, remote.