guard band

Noun

 * 1)  An unused part of the radio spectrum between bands, for the purpose of preventing interference.
 * 2) The unrecorded space between tracks on magnetic tape or other media which prevents the signals on adjacent tracks from interfering with each other.
 * 3)  The amount by which minimum product specifications are increased to ensure that, even with measurement uncertainty, the product will meet the minimum specifications with a specified level of confidence.
 * 4)  A virtual area of the screen, bordering the real screen, to which any rendering is ignored, used to simplify clipping.