The most common and most likely answer to this crossword clue is the 8 letter word JACKETED
I've seen this crossword clue in The Times
J
A
C
K
E
T
E
D
Buddy explains!

The straight part
We know that "In case" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in case = jacketed.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 JACKETED mean?
JACKETED verb- To enclose or encase in a jacket or other covering.
- Dressed in a jacket (of a specified kind).
- Encased or enclosed inside a jacket (of a specified kind).