HH

1. His or Her Highness
2. His Holiness

HH or 2H

Very hard (on lead pencils)

• radian
• radiance
• radiances
• radiancies
• radiancy
• radians
• radiant
• radiant energies
• radiant energy
• radiant heat
• radiantly
• radiants
• radiata
• Radiata
• radiata pine
• radiatas
• radiate
• radiated
• radiately
• radiates
• radiating
• radiation
• radiational
• radiation belts
• radiation oncologist