Noun
a strongroom or compartment (often made of steel) for safekeeping of valuables
Source: WordNetThe best efforts of human scientists in this direction seemed comparable to those of Stone Age men trying to break through the armour of a bank vault with flint axes. Arthur C. Clarke
Let's restore sanity and fairness to the tax cut conversation. We simply cannot afford to hand over the bank vault to our nation's millionaires and billionaires while the middle class picks up spare change. Paul Tonko