A vulgar description used to describe the breasts of an aging women. The plumb bobby state is reached once the nipples become the lowest part of the breasts (as opposed to the central part), and actually point straight down. They have the general appearance of plumb bobs pointing to the ground.
I don't like looking at National Geographic because all of the women have plumb bobbies!
by Jane Lindquist March 12, 2006
Can you define these popular missing words?