A royal flag from the West African nation (7)
I believe the answer is:
eritrea
'african nation' is the definition.
(country in Africa)
'a royal flag from the west' is the wordplay.
'royal' becomes 'er' (abbreviation for Elizabeth Regina).
'flag' becomes 'tire' (both can mean to become weary).
'from the west' shows that the letters should be reversed in order.
'a'+'er'+'tire'='aertire'
'aertire' back-to-front is 'ERITREA'.
(Other definitions for eritrea that I've seen before include "Asmara area" , "nation" , "North-east African state" , "Country to the north of Ethiopia" , "Eire art (anag)" .)