ground zero > define
noun
- The target of a projectile (as a bomb or missile. )
- The site of the World Trade Center before it was destroyed.
- The point of detonation (or above or below) of a nuclear weapon. .
by WordNet 3.0 © 2006 by Princeton University
(DoD, NATO) The point on the surface of the Earth at, or vertically below or above, the center of a planned or actual nuclear detonation. See also actual ground zero; desired ground zero.
by Department of Defense Dictionary of Military and Associated Terms. 31 January 2011.