The most common and most likely answer to this crossword clue is the 7 letter word EXCRETA
I've seen this crossword clue in Financial Times
E
X
C
R
E
T
A
Buddy explains!
The straight part
We know that "Discharge" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case discharge = excreta.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 EXCRETA mean?
EXCRETA noun- Bodily waste which is excreted from the body.