noun [ U ]
1.
the point on the earth's surface where a nuclear bomb explodes
2.
Ground Zero the site of the World Trade Center in New York, destroyed on 11 September 2001
3.
the beginning; a starting point for an activity
noun [ U ]
1.
the point on the earth's surface where a nuclear bomb explodes
2.
Ground Zero the site of the World Trade Center in New York, destroyed on 11 September 2001
3.
the beginning; a starting point for an activity
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005