sky wave

noun Radio.

a radio wave propagated upward from earth, whether reflected by the ionosphere or not.

Origin of sky wave

First recorded in 1925–30

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for sky wave

sky wave

noun

a radio wave reflected back to the earth by the ionosphere (ionospheric wave), permitting transmission around the curved surface of the earthCompare ground wave

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012