an unassigned range of radio frequencies either just above or just below the band of frequencies required for the signal transmitted by a broadcasting station. It helps to prevent interference in receivers between signals from different stations.
Origin of guard band
First recorded in 1955–60
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a space left vacant between two radio frequency bands, or between two tracks on a magnetic tape recording, to avoid mutual interference
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