Country extra worthless to Scots (7)
I believe the answer is:
andorra
'country' is the definition.
(Andorra is an example)
'extra worthless to scots' is the wordplay.
'extra' becomes 'and' ('and' means in addition to).
'worthless to scots' becomes 'orra' (Scottish term meaning idle or worthless).
'and'+'orra'='ANDORRA'
(Other definitions for andorra that I've seen before include "Tax haven" , "Territory" , "microstate" , "Semi-independent country in Pyrenees" , "Principality in SW Europe" .)