primacy /prīˈmə-si/

1. The (condition of being in) the position or place that is first in rank or importance
2. The office or rank of a primate

• radio-thorium
• radiotoxic
• radio wave
• radio waves
• radish
• radishes
• radium
• radium A
• radium B
• radium bomb
• radium bombs
• radium emanation
• radiums
• radius
• radiuses
• radius of curvature
• radius vector
• radius vectors
• radix
• radome
• radomes
• radon
• radons
• rads
• radula