The most common and most likely answer to this crossword clue is the 5 plus 3 plus 6 letter word DRESS FOR DINNER
D
R
E
S
S
F
O
R
D
I
N
N
E
R
Buddy explains!

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.