What is this hose called on the throttle body?

[Pazzo]

What is this hose called? I tried to shove it back on and didn't seem to want to go back. I pulled this off while I was redoing the plenum gasket.

 

[Dredger]

That's a vacuum line and you appear to be missing the majority of the rubber hose that connects the line to the throttle body. Here's a pic to show you what's missing (any auto parts store should have rubber hose):

 

[Pazzo]

Thank you. Guess it should have been obvious to me.