The most common and most likely answer to this crossword clue is the 9 letter word DIGESTIVE
I've seen this crossword clue in Financial Times
D
I
G
E
S
T
I
V
E
More clues leading to the result DIGESTIVE
Buddy explains!

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 DIGESTIVE mean?
DIGESTIVE noun- A substance that aids digestion.
- A digestive biscuit.
- Of, relating to, or functioning in digestion.
- That causes or promotes digestion.