I am using trustworthy casinos and bookies, but if I win, I withdraw the winning immediately. I play for fun, I am using little amount of money, but I prefer to cash out and use the money for weekend.
as that is what His friend experienced .
after winning a good amount , His friend chooses to let the money stays in casino so in the end , he losses it all.
not like when he cashed our the winning and use for other expenses , so maybe he will not lose if all like that.
but yeah I do understand the term uses in sports betting ..