A thin lad abandoned country (8)
I believe the answer is:
thailand
'country' is the definition.
(Thailand is an example)
'a thin lad abandoned' is the wordplay.
'abandoned' is an anagram indicator.
'a'+'thin'+'lad'='athinlad'
'athinlad' anagrammed gives 'THAILAND'.
(Other definitions for thailand that I've seen before include "Former Siam" , "Formerly Siam" , "Asian nation" , "Southeast Asian country" , "Modern Siam" .)