If one lend money to a gambler that means the lender too is also gambling because there are always a possibility that the gambler might lose or win but if the gambler win, with the joy in him or her, they might give you back the money or even add extra to it, but just imagine if the gambler lose the money you lend to him or her.
As there is no sure odds in gamble, I don't think a gambler can always.
You can say a lender giving out loans to people without demanding anything as collateral is gambling with his funds as well. But it’s a gamble that the lender is willing to take. Having already known the lender and his capabilities, the lender might have (non ethical) ways of getting his money back from people that might default on their payments.
While I don’t think any reputable financial institution or any sane person would give away loans for the purpose of gambling, there are always people who would still give loans for such purposes.
Let me say you are scattering points altogether, and for clarification, I believe what @rachael9385 says, that anyone who is avoiding gambling but loaning gamblers his money is also gambling. This is not a direct definition of gambling, but technically, such a person is gambling as the gamblers who could deem it feet to use the amount that is not advisable to gamble for the purpose may not pay back the money.
To access a loan for gambling is just out of sense and the person engaging in such an act is irresponsible. Now tell me, how would irresponsible people pay their loans? They will prepare to gamble more with it. Fine, some would pay it but I can assure you that the percentage will be little compared to those who accessed the loan. This is dangerous, and to make matters worse, the loaner still didn't plan collaterals as a condition to get the loan, this is unwise. No matter what makes you think that he has other means to collect the money, the defaulter will be many, and loan default is not a crime under the law, again, the table is still not in your favour here. You can also see this with many desperate loan companies that do not collect collateral, there are enough defaulters, which is why I can't ever engage in such a thing. It might be smart to give gamblers loans by investing in their weakness but it's bad for businesses not to have something to make them accountable for the loan taken.