parallel parallelbeing an equal distance apart everywhere, extending in the same direction, never meeting or intersecting Related Articles: Glossary: plane waveDistributed acoustic sensing (DAS): Shedding light on passive acoustics – September 20, 2023DOSITS VideosTutorial: What is Sound?Science Tutorial: What is Sound?What is sound?How do marine invertebrates produce sounds?GeophoneSounds Associated with AggressionLeopard Seal Derek Sutcliffe2017-02-26T20:10:00-05:00