The most common and most likely answer to this crossword clue is the 4 letter word DUPE
I've seen this crossword clue in The Times
D
U
P
E
More clues leading to the result DUPE
- Chump expected to keep quiet
- Fool expected to seize power
- Chump expected to seize power
- Trick expected to take in chump finally
- Fool appointed to carry piano
- Rejected a portion of rice pudding and fool
- Trick unionists’ alliance, ultimately
- Fool expected to carry cash
- Patsy‘s English, looked down on by Irish party
- Trick of the French to forego training
Buddy explains!

The straight part
We know that "Chump" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case chump = dupe.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 DUPE mean?
DUPE noun- A person who has been deceived.
- To swindle, deceive, or trick.
- A duplicate of a photographic image.
- (restaurant industry) A duplicate of an order receipt printed for kitchen staff.
- A duplicate.
- To duplicate.