adjective
(aviation, military) Pertaining to the ejection of the occupant of an aircraft from a grounded stationary position (i.e. zero altitude and zero airspeed).
(aviation) Pertaining to weather conditions of zero ceiling and zero visibility (i.e., opaque cloud all the way down to ground level), or to aircraft operations in such conditions.
(military) Involving neither of two powers increasing their stockpile of nuclear weapons.