(*) In nuclear warfare: 1. The horizontal distance which, when added to the radius of safety, will give the desired assurance that the specified degree of risk will not be exceeded. The buffer distance is normally expressed quantitatively in multiples of the delivery error. 2. The vertical distance which is added to the fallout safe-height of burst in order to determine a desired height of burst which will provide the desired assurance that militarily significant fallout will not occur. It is normally expressed quantitatively in multiples of the vertical error.