The most common and most likely answer to this crossword clue is the 5 letter word MISDO
I've seen this crossword clue in The Guardian
M
I
S
D
O
More clues leading to the result MISDO
- Do wrong, offering paste, pocketing diamonds
- Mess up a quantity of goods imported from the east
- Those starting modestly in speed event perform badly
- Party girl mostly first to act badly
- Make a mess of date coated in soya bean paste
- Make a mess of paste for flavouring – little density in it
- Bungle military intelligence’s event
- Harm is done inhaling fluff
- Botch it up and set diamonds
- Flub in form is doubted
Buddy explains!
The straight part
We know that "to act badly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to act badly = misdo.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.