Thing about alcohol is it makes you really honest. Like, too honest. There's an amount of drunkenness which comes after tipsy but before black-out. It's not that you just say every single thing that pops into your head. It's more that you get it into your brain that honesty is the best policy in all situations – something which we all agree with in principle but all acknowledge there are exceptional cases.
One such case, would be one where you have met someone on no less than three occasions and you introduced yourselves on the first occasion, you asked for her name again on the second occasion because you've forgotten it and realised on the third occasion that you have forgotten her name again but you know she has remembered your name because she has already called you by it several times already.
There are several ways of getting around this. You could, for example, ask one of her friends for her name. This course of action is a tacit admission on your part that you really should have remembered the name by now and you have had to resort to indirect tactics to make up for your failings as a decent human being. You acknowledge the shame and try to find a way to avoid facing it.
Of course, if you do resort to this method, it is important to make sure to commit the name to memory before getting on with an evening of heavy drinking because alcohol famously has a negative impact on short term memory. Otherwise you will yet again forget the name and find yourself back to square one except now you're drunk which makes everything more difficult.
Another reasonable and sneakier course of action, is to acutely listen to anyone who makes conversation with the person whose name you have forgotten and see if they use it. It's more difficult to pull off than simply asking one of her friends but is even more effective if done successfully since now nobody will ever know that you've forgotten her name at all.
Being drunk can be a bit of a hindrance in trying to carry out this plan out but doesn't make it impossible. What does make it impossible is being in a very loud club where you can barely hear what people are saying to you let alone what they might be saying to her.
So the last thing you can do is simply not use her name at all and never place yourself in a situation where you might need to know her name. Don't let her give you her number because you will need to know her name when typing it into your phone. Don't talk to her about anything you saw online you think she might be interested in as she might ask you to send it to her and then you'll have to go find her on Facebook which is an impossibility for you in that moment. Just go the entire evening without ever calling out to her and if you do find yourself needing her attention, well, too bad, you should have remembered her name then. Then once the evening is over, you go your separate ways and do your best to avoid her for the rest of your life.
Any of these solution are totally acceptable and can easily be pulled off with a little bit of tact and consideration.
What you don't do is go up to this person and straight up tell her you forgot her name again. And what you definitely don't do is go up to this person and tell her that you forgot her name again but that it's fine because names are really arbitrary and difficult pieces of information to retain and what's actually important is remembering the person's face and the things you've learned about them through conversation because then the person might ask you what you've learned about her through conversation to which the answer is obviously nothing because you haven't even gone as far as remembering her damn name so you end up standing there with nothing to say as she shakes her head and walks away from you like the inconsiderate idiot you are.
Trust me, you don't want to do that.