The most common and most likely answer to this crossword clue is the 11 letter word DISHEVELLED
I've seen this crossword clue in The Times
D
I
S
H
E
V
E
L
L
E
D
More clues leading to the result DISHEVELLED
- Tousled beauty had fun going topless
- Untidy woman in low bar was first to drink litres
- Attractive person, temptress by valley returning ill-groomed
- Lovely to replace student at top of flat that's untidy
- Messy food first lady, learner produced
- Food first woman learner presided over was messy
- Messy plate, smoothed, left out
- Scruffy beauty was merry after shaving head
Buddy explains!

The straight part
We know that "untidy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case untidy = dishevelled.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 DISHEVELLED mean?
DISHEVELLED verb- To throw into disorder; upheave.
- To disarrange or loosen (hair, clothing, etc.).
- To spread out in disorder.
- (of a person) With the hair uncombed.
- (by extension) Disorderly or untidy in appearance.