The unfortunate (but often hilarious) result of a busty woman fitting herself into a swimsuit too small for her body. The suit's tight fabric crushes her breasts together, creating a single, enormous boob in the center of her chest.
D00d, that chick's monoboob is outta control! She looks like a boobclops
monoboob - gene disorder in which females are born with a morphed gene that results in the growth of a 'double boob'. Operations can be carried out to separate the monoboob but this is a risky process as it is so close to the heart. Although, a scan can be done at birth if the child is to thought to have this gene (inherited from parents) which enables them to see the gene and split it or remove a part of this which would result in the normal growth of breasts on the child.
when a woman is so fat her boob get hidden by a huge roll of fat, creating the illusion of one long boob across her body. its a pretty nasty look.
girl: have you seen that new chemistry teacher? she has a total monoboob!