Search Result for "ground zero":
Wordnet 3.0

NOUN (3)

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; 



WordNet (r) 3.0 (2006):

ground zero
    n 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