The most common and most likely answer to this crossword clue is the 4 letter word GOWN
G
O
W
N
More clues leading to the result GOWN
Buddy explains!

The straight part
We know that "dress" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dress = gown.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 GOWN mean?
GOWN noun- A loose, flowing upper garment.
- A woman's ordinary outer dress, such as a calico or silk gown.
- The official robe of certain professional men and scholars, such as university students and officers, barristers, judges, etc.
- (by metonymy) The university community.
- A loose wrapper worn by gentlemen within doors; a dressing gown.
- Any sort of dress or garb.
- The robe worn by a surgeon.
- To dress in a gown, to don or garb with a gown.