The most common and most likely answer to this crossword clue is the 4 plus 4 plus 5 letter word LOSE ONES SHIRT
I've seen this crossword clue in The Times
L
O
S
E
O
N
E
S
S
H
I
R
T
More clues leading to the result LOSE ONES SHIRT
Buddy explains!
The straight part
We know that "Get dressing down as result of gambling disaster" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case get dressing down as result of gambling disaster = lose ones shirt.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.