BDE is "big dick energy". The term is mostly used when you spot someone that either has done or is doing something that would make them have a big dick.
Person : Have you seen Sp3ngy over there.
Person 2 : Yeah I've seen him he is overflowing with BDE
BDE stands for Big Dick Energy. BDE can be defined a couple ways. 1. Giving off energy that the male has a large penis. 2. Confidence without cockiness.