The most common and most likely answer to this crossword clue is the 6 letter word DECOCT
I've seen this crossword clue in The Guardian
D
E
C
O
C
T
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 DECOCT mean?
DECOCT verb- To make an infusion.
- To reduce, or concentrate by boiling down.
- To heat as if by boiling.
- To reduce or diminish.
- To digest in the stomach.
- To devise.