A question raised when presented with a shocking or almost unbelievable statement. Could also represent a statement used to determine the trustworthiness of the speaker.
Note: 'say word' functions as a rhetorical question. 'Word' is not an appropriate answer to the question

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.

When you hear something, but you don't believe it, usually out of shock.

Pretty much when you agree with something.

A certain way that you can answer your cell when you are in a major rush. You have no time to mess around with proper greetings. If the person calling does not say words quickly enough, you hang up. They can try again later.

A certain way that you can answer your cell when you are in a major rush. You have no time to mess around with proper greetings. If the person calling does not say words quickly enough, you hang up. They can try again later.
*Ring Ring Ring*
You: "Say Words!"
Caller: *Silence for 5 seconds*
You: *Click - Hangs Up Phone*

It means "really??" or "no way!!"