D1

Short for "D1 glazer' or "D1 dickrider".
Someone who excels in the art of "glazing", which is either giving excessive compliments or sometimes used as just talking about a particular person a lot, like having them on your mind and in your mouth 24/7.

Guy 1: Man, I can't stand Jeff dude! He's always dickriding me.
Guy 2: Sounds like he's D1.