anacoustic

[ an-uh-koo-stik ]

adjective

1. of or relating to the upper portion of the earth's atmosphere and to interplanetary space, where sound cannot be transmitted because molecules are too far apart to serve as a transmitting medium.

anacoustic

/ ˌænəˈkuːstɪk /

adjective

1. unable to support the propagation of sound; soundless

Word History and Origins

Origin of anacoustic¹

an- ¹ + acoustic