palladium

noun

1. A safeguard.

   “The trial by jury is the Palladium of our civil rights.”

   “[H]ow unspeakably ominous to dim Royalist participators; for whom Royalism was Mankind's palladium[.]”

   “The presupposition of the Prometheus myth is to be found in the extravagant value which a naive humanity attached to fire as the true palladium of every ascending culture.”

2. (countable, uncountable)A chemical element (symbol Pd) with an atomic number of 46: a rare, lustrous silvery-white metal.
3. (countable)A single atom of this element.

name

1. A wooden statue of great antiquity on which the safety of Troy and later Rome was said to depend.