ground zero meaning

• Noun: ground zero  grawnd 'zi(u)row
  1. The target of a projectile (as a bomb or missile) 
  2. The site of the World Trade Center before it was destroyed 
  3. The point of detonation (or above or below) of a nuclear weapon

  Type of: land site, point, site, target, target area

  Part of: Big Apple, Greater New York, New York, New York City, NYC

  Encyclopedia: Ground zero

• 
  [Defence]
  (*) 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.

• actual ground zero:    [Defence] (*) The ...
• desired ground zero:    [Defence] (*) The ...
• zero:    Noun: zero (zeros, ...

Examples

1. consider, first, a location 22 miles downwind from ground zero.
2. an actual contact surface burst leads to the highest possible overpressures near ground zero.
3. some buildings leaned away from ground zero as though struck by a wind of stupendous proportions.
4. this assumption is reasonably justified in the early stages, when the wave front is not far from ground zero.
5. my compliment to the ground zero medical workers