The most common and most likely answer to this crossword clue is the 7 letter word NUTCASE
I've seen this crossword clue in The Daily Telegraph
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More clues leading to the result NUTCASE
- Legal action taken by head, a very foolish person
- Crackpot’s proceedings against teachers?
- Suet can ruin fruitcake
- A foolish person going round Brazil?
- Crazy type going round Brazil?
- Constables act unlawfully, holding back lunatic
- No Trump action about WMD material? He’s crazy
- Cook can’t use fruitcake
- Crackpot, name unknown, joining a sect that’s crazy
- Madman gives teachers box of wine
Buddy explains!

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 NUTCASE mean?
NUTCASE noun- An eccentric or odd person.
- Someone who is insane.