A married woman in the New World (7)
I believe the answer is:
america
'the new world' is the definition.
(the New World means the Americas)
'a married woman' is the wordplay.
'married' becomes 'm' (abbreviation, e.g. in genealogy).
'woman' becomes 'erica' ().
'a'+'m'+'erica'='AMERICA'
'in' acts as a link.
(Other definitions for america that I've seen before include "United States" , "World power" , "Curious camera I take to the continent" , "country targeted by 3 [ROMNEY]" , "The superpower" .)