An ornamant worn by the male of the human species to create the illusion that his reproductive organ is more special than the others in his group. The DSCR also creates the illusion that the owner is wealthy and can provide a very lavish lifestyle for the female he is courting.
DSCR's made of non precious stones have been found. These might be used by the lower class of males to attract the gold digger in an attempt to mate with a more beautiful female.
Dude 2: "Oh yeah? Did it work?"
Dude 1: "Hell yeah, when you have diamonds on your cock the girls just want it!!"