dry, when in relation to wine , refers to the sweetness, or left over 'residual' sugar that was used for the fermentation process. It's dry when all the sugar was combined with the yeast - or sweet if there was sugar remaining once the process stopped... medium is, well, somewhere in between. kind of like this definition. useful, moderately interesting, but no oxford definition.

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.