The most common and most likely answer to this crossword clue is the 11 letter word CONFIDENCES
I've seen this crossword clue in The Times
C
O
N
F
I
D
E
N
C
E
S
Buddy explains!
The straight part
We know that "secrets" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case secrets = confidences.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 CONFIDENCES mean?
CONFIDENCES noun- Self-assurance.
- A feeling of certainty; firm trust or belief; faith.
- Information held in secret.
- Boldness; presumption.