The most common and most likely answer to this crossword clue is the 5 letter word NUTTY
I've seen this crossword clue in The Times
N
U
T
T
Y
More clues leading to the result NUTTY
- Out to lunch — like some fruit?
- Like Brazil? Unhinged!
- Cracked head? Totally gutted
- Fruity bananas
- Absurd as satay sauce?
- Like muesli and bananas?
- Mad group of teachers meeting heads of third year
- Bolt’s partner initially two yards round the bend
- Teachers totally discontented? That’s mad
- Unhinged like a group of teachers?
Buddy explains!

The straight part
We know that "Unhinged!" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case unhinged! = nutty.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 NUTTY mean?
NUTTY adjective- Containing nuts.
- Resembling or characteristic of nuts.
- Barmy, crazy, mad.
- Extravagantly fashionable