The most common and most likely answer to this crossword clue is the 3 plus 4 plus 3 letter word BAD HAIR DAY
I've seen this crossword clue in The Guardian
B
A
D
H
A
I
R
D
A
Y
More clues leading to the result BAD HAIR DAY
- Having dodgy locks is when mishaps occur
- Braid had unravelled, indeed — one of these?
- When one might suffer an awful shock?
- Period during which you might have an unpleasant shock?
- When to expect a nasty shock?
- Troubling time when your locks play up?
- When a shock is even harder to bear?
- A dreadful shock this time when everything goes wrong?
- Hard time a coot presumably doesn’t have?
- Time when nothing goes right in musical put on outside during recess
Buddy explains!
The straight part
We know that "When to expect a nasty shock" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case when to expect a nasty shock = bad hair day.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.