usually said when you already knew what one person is talking about or totally obvious. also said in place of "duh!", "no shit!", "really (note the sarcasim)?" or "well, no kidding!"
a der is something you would call a hick. the gods “jansens” and “dpolicatastrophe” invented it as a way to stay “okay” “whatever” “k”, etc. but after it was soon evolved to describe the gods. the ders are in eternal war with the sills.
German for "the". Sounds like "duh", or "dah", so this would explain why "der" is used as "duh" in this day and age. Or maybe because it sounds funnier.
"Der launch the missile!"
"*spinning a cat around in one hand*Deeerrrrr hi I'm Rob I'm the biggest idiot in the whole wide world!"