Strangely enough, that's the technical term for this desoldering vacuum tool. Useful in cleaning up mistakes, every electrical engineer has one of these on their desk.
To use, depress the end to engage the vacuum. Then heat up the to-be-desoldered joint until it is liquid. With your other hand hold the plastic tip as close as possible to the joint and depress the button to suck up all the liquid solder. If necessary, clean up the remaining solder with wick.