Clee-Vag
Exposing your vagina, just as one would expose too much chest.

full of cleavage, when tits are at there best viewable state, yet still not completly visible

the visible gap between a woman's breasts. Zero gap preferred, 1/2" is interesting, 3" is boring, 5" is too much.

The reason I failed classes in high school.

One of the best things in life

The visible by-product when a woman wears a bra/corset/top that pushes her breasts together.
Sometimes used purposly as an attraction technique when tartish girls want shallow guys attentions.

Cleavage is the most important thing in the world for most men or they just don't care. Also you can compare it to the sun. You can't stare at it to long, it's to risky.