noun: a metal coating that is applied to ships to protect the hull against salt water. It must be reapplied/replaced every so often, like brake pads, or a cell phone screen protector.
Disambiguation: any sort of temporary protective coating, veneer, or barrier.
Metaphorically — fine rhetoric disguising or encapsulating a shoddy argument. A fresh layer of paint on a crumbling house.
The golden record uses a thin layer of gold as a sacrificial anion to protect the record against vacuum of space.