The most common and most likely answer to this crossword clue is the 9 letter word THROWSTER
T
H
R
O
W
S
T
E
R
Buddy explains!
The straight part
We know that "Gambler" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gambler = throwster.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 THROWSTER mean?
THROWSTER noun- One who twists or spins silk to prepare it for weaving.
- A gambler; one who throws dice in gambling.