infrasonic /in-frə-sonˈik/ (acoustics)

1. (of frequencies) below the usual audible limit
2. Of, using or produced by infrasonic vibrations or pressure waves

• rickshaws
• rickstand
• rickstands
• rickstick
• ricksticks
• rickyard
• rickyards
• RICO
• ricochet
• ricocheted
• ricocheting
• ricochets
• ricochetted
• ricochetting
• ricotta
• ricottas
• ric-rac
• RICS
• rictal
• rictus
• rictuses
• ricy
• rid
• ridabilities
• ridability