After five years, you'll be fully 'vested' in the company pension plan. [=you will have earned the right to get a full pension when you retire]
Congress is 'vested' with the power to declare war. = The power to declare war is 'vested' in Congress.
She has a 'vested interest' in seeing the business sold, as she'll make a profit from the sale.
(..) I'll start smokin' 'em. Wait, wait, wait... Go back! They will kill you! They will kill you! Go back! No vest. All clear. Whoa, fucking shit. Usamah... Usamah... Usamah... (..)2012 Zero Dark Thirty