Lethal Dosage. L.D. is a pharmacological term used by the medical industry to standardize the toxicity of chemicals, specifically. In huge medical books, medical scientists and doctors have a standardisation for every single thing that you can possibly have in your body.
L.D. Has an amazing personality. He knows how to have a good laugh and have a good time. He's always there to cheer you up when you feel blue. He cusses a bunch and even talks dirty sometimes, but he's super cool. And the one thing he will never do is let down his girl. He always lets her know he loves her and wouldn't do anything to hurt that.
Girl 1: That guy is such a L.D.
Girl 2: I know! I wish he liked me though!