Bridge crossing a line in the country (5)
I believe the answer is:
spain
'the country' is the definition.
(Spain is an example)
'bridge crossing a line' is the wordplay.
'bridge' becomes 'span' (synonyms).
'crossing' becomes 'i' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a line' is an insertion indicator.
'span' placed around 'i' is 'SPAIN'.
'in' is the link.
Can you help me to learn more?
(Other definitions for spain that I've seen before include "It pains one to be out in this country" , "country of mostly dry mountains, going by air" , "ditto" , "Kingdom" , "holiday destination?" .)