The most common and most likely answer to this crossword clue is the 8 letter word FURROWED
I've seen this crossword clue in The Times
F
U
R
R
O
W
E
D
Buddy explains!

The straight part
We know that "wrinkled" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wrinkled = furrowed.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 FURROWED mean?
FURROWED verb- To cut one or more grooves in (the ground, etc.).
- To wrinkle.
- To pull one's brows or eyebrows together due to concentration, worry, etc.