The most common and most likely answer to this crossword clue is the 5 letter word QUACK
I've seen this crossword clue in Financial Times
Q
U
A
C
K
Buddy explains!
The straight part
We know that "Cry coming from Donald/possibly a charlatan" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cry coming from donald/possibly a charlatan = quack.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 QUACK mean?
QUACK noun- The sound made by a duck.
- To make a noise like a duck.
- A fraudulent healer or incompetent professional; especially, a doctor of medicine who makes false diagnoses or inappropriate treatment; an impostor who claims to have qualifications to practice medicine.
- A charlatan.
- A doctor.
- To practice or commit quackery (fraudulent medicine).
- To make vain and loud pretensions.
- Falsely presented as having medicinal powers.