Antelope crossing borders of neighbouring country (7)
I believe the answer is:
england
'country' is the definition.
(England is an example)
'antelope crossing borders of neighbouring' is the wordplay.
'antelope' becomes 'eland' (eland is a kind of antelope).
'crossing' means one lot of letters goes inside another.
'borders of' says to hollow out the word (remove centre letters).
'neighbouring' with its middle taken out is 'ng'.
'eland' enclosing 'ng' is 'ENGLAND'.
(Other definitions for england that I've seen before include "Lend nag to the neighbour" , "' - - expects' (Nelson)" , "Largest country in the UK" , "Part of the UK" , "European country" .)