1. Of sound waves with frequency greater than 1000 million hertz 
2. Moving at more than five times the speed of sound

Encyclopedia: Hypersonic

• contemptibility
• contemptible
• contemptibly
• potentiate
• potentiation
• Potentilla
• Potentilla anserina
• potentiometer
• potently
• Poterium
• Poterium sanguisorba
• potful
• pothead
• pother
• potherb
• potholder
• pothole
• potholed
• potholer
• pothook
• pothos
• pothouse
• pothunter
• potion
• potlatch