Often used in gang related activity, to either:
A. "Wack" somebody.
or
B. Make sure the bastard looking at your wife/girlfriend never again sees the light of day.

Cement shoes often consist of large block structured cement molds that fit perfectly around one's feet. The person sporting these trendy accessories is then thrown into a river, lake, ocean, or off of a bridge. Cement is used to asure the hitman, or average John that decides to murder his neighbor for having an affair with his wife, that the victim of this act does not float back to the surface.

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.

A game played by one's self or between friends that requires all parties to finish whatever alcoholic beverages they have in their vicinity without standing up. No bathroom breaks are allowed until the beverages are finished, and the end goal of this drinking game is to get so drunk it is almost impossible to stand back up.

When you are running from the cops, its hard to do, so it's like you're wearing cement shoes.