Does anyone know what true retainer fees mean?

I hired an attorney to represent me and he asked me for a quite large amount of money. He mentioned that will be a true retainer.Does anyone know what true retainer fees mean?
A retainer is supposed to be deposited in the lawyer's client trust account and remain the property of the client until used for fees or expenses. Some lawyers might misuse the term ';retainer'; to mean ';minimum fixed fee.'; That is not a retainer, it is a minimum fixed fee. Nothing illegal about it, but make sure the lawyer is clear. No doubt his engagement agreement will spell out what he means by a ';true retainer.';Does anyone know what true retainer fees mean?
A retainer is an amount of money a attorney may request in order to represent you. In most cases, it is non refundable, though credited against any fees incurred in your case.





Some attorneys will return unused portions of your retainer, but it is strictly up to the attorney.
It means that you give him a down payment and if you lose, you also lose your money and then you have to pay him the rest.