The most common and most likely answer to this crossword clue is the 7 letter word TWOFOLD
I've seen this crossword clue in The Times
T
W
O
F
O
L
D
Buddy explains!

The straight part
We know that "Double" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case double = twofold.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 TWOFOLD mean?
TWOFOLD adjective- Double; duplicate; multiplied by two.
- Having two parts, especially two different parts.
- In a double degree; doubly.