The most common and most likely answer to this crossword clue is the 3 letter word POX
I've seen this crossword clue in Financial Times
P
O
X
More clues leading to the result POX
Buddy explains!
The straight part
We know that "Disease" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case disease = pox.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 POX mean?
POX noun- A disease characterized by purulent skin eruptions that may leave pockmarks.
- Syphilis.
- A curse.
- To infect with the pox, or syphilis.