Of women, when one's (bra) cup runneth over slightly, marring slightly the smooth convex curve of bra and boob-top. A tiny amount of overboobage is intriguing, but excessive overboobage leads to the much-feared four-boob effect. Overboobage is most prevalent in push-up bras, but can be found in any over-tight bra that is not full-coverage.

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.