HH

1. His or Her Highness
2. His Holiness

HH or 2H

Very hard (on lead pencils)

• trithionic
• trithionic acid
• tritiate
• tritiated
• tritiates
• tritiating
• tritiation
• tritiations
• tritical
• triticale
• triticales
• tritically
• triticalness
• triticalnesses
• triticeous
• triticism
• triticisms
• Triticum
• tritide
• tritides
• tritium
• tritiums
• Tritoma
• triton
• Triton