infrasonic /in-frə-sonˈik/ (acoustics)

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

inˈfrasound noun

• sloot
• slop
• slop basin
• slop basins
• slop bowl
• slop bowls
• slop bucket
• slop buckets
• slop-built
• slop-chest
• slop-chests
• slop-clothing
• slope
• slope arms
• sloped
• slope off
• slopes
• slopewise
• slopier
• slopiest
• sloping
• slopingly
• slop out
• slop pail
• slopped