1. Derived from Prussian blue 
2. Of, or derived from prussic (hydrocyanic) acid
   - hydrocyanic

Encyclopedia: Prussic

• Arkansas kingbird
• Arkansas River
• Arkansawyer
• arkose
• arles
• Arlington
• arm
• arm bone
• arm candy
• arm exercise
• arm in arm
• arm pad
• arm's length
• arm-twisting
• armada
• Armadillidiidae
• Armadillidium
• armadillo
• Armageddon
• Armagnac
• armament
• armamentarium
• Armand Jean du Plessis
• Armata Corsa
• armature