brig

A two-masted vessel, square-rigged on both foremast and mainmast

A jail or guardhouse, especially in a naval military prison or jail on a ship, navy base, or (in fiction) spacecraft.

To merely pretend to be occupied, to lollygag.

To jail, to confine into the guardhouse.

Bridge.

Now do thy speedy utmost, Meg, / And win the key-stane of the brig;