Fellow hiding close to boundary to damage country (7)
I believe the answer is:
myanmar
'country' is the definition.
(Myanmar is an example)
'fellow hiding close to boundary to damage' is the wordplay.
'fellow' becomes 'man' (fellow can mean a man).
'hiding' means one lot of letters goes inside another.
'close to' indicates one should take the final letters (the close/ending of).
'to damage' becomes 'mar' (to mar is to spoil or damage).
The last letter of 'boundary' is 'y'.
'man' going around 'y' is 'myan'.
'myan'+'mar'='MYANMAR'
(Other definitions for myanmar that I've seen before include "Yangon is its capital" , "Far East location" , "state since military regime" , "Country of SE Asia" , "Another name for Burma" .)