aspis

noun3

1. •
   (historical) A type of round shield borne by ancient Greek soldiers.

   • "shield both large and tough" has never said that aspides are small and weak […] — 1963
2. •
   A prominent ring of thickened exine around a pore on a pollen grain
3. •
   (no longer used) An asp or generic venomous snake

   • Flesh dipped in the sea Aegeum will never be sweet; the herb Trigion being once bit with an aspis never groweth, and conscience once stained with innocent blood is always tied to a guilty remorse. — 1588