infrasonic /in-frə-sonˈik/ (acoustics)

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

• airing
• airing cupboard
• airing cupboards
• airings
• air-intake
• air-intakes
• approvances
• approve
• approved
• approved school
• approved schools
• approver
• approvers
• approves
• approving
• approvingly
• approx.
• approximal
• approximate
• approximated
• approximately
• approximates
• approximating
• approximation
• approximations