Artist tours Arab Republic (7)
I believe the answer is:
romania
'republic' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'artist tours arab' is the wordplay.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'tours' indicates putting letters inside (to tour can mean to go around).
'arab' becomes 'omani' (Omani is an example).
'ra' placed around 'omani' is 'ROMANIA'.
Can you help me to learn more?
(Other definitions for romania that I've seen before include "Eastern European country" , "I'm Aaron in Europe" , "East European country" , "Country of eastern Europe" , "Oman air in the eastern European state" .)