Bladdered is a very casual British way to say someone is extremely drunk — not a little happy from a drink, but full of alcohol and showing it. You hear it among friends after a night out, and in loud newspapers. You would not write it in school work or say it to a teacher. It is bladder (the bag in your body that holds urine) plus -ed, as if the person were filled up. That picture is probably why the word feels right — drink fills you — though actually nobody uses it as a medical word. Americans almost never say this; they might say wasted or smashed. It can sound a bit crude, so it is a word to understand more than to use in class.

喝掛了、爛醉（英式很口語，偏粗）。