The most common and most likely answer to this crossword clue is the 4 letter word BOZO
I've seen this crossword clue in Financial Times
B
O
Z
O
More clues leading to the result BOZO
- Fool with Dickens over …
- Head of Blackpool Zoo, bumbling buffoon
- Dickens “ordinary”? Idiot!
- American guy carries little weight – he’s a bit dim
- Stupid man – to begin, Boris half starting Zoom
- Dickens’s Oliver, at the beginning, is a fool
- Idiot’s to voice disapproval of madhouse without repetition
- Abandoned booze but not Ecstasy or dope
- Shocker catching zip at first —idiot
Buddy explains!

The straight part
We know that "idiot" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case idiot = bozo.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 BOZO mean?
BOZO noun- A stupid, foolish, or ridiculous person, especially a man.