Group of states I often read about (10)
I believe the answer is:
federation
'group of states' is the definition.
(I've seen this before)
'i often read about' is the wordplay.
'about' indicates anagramming the letters.
'i'+'often'+'read'='ioftenread'
'ioftenread' is an anagram of 'FEDERATION'.
(Other definitions for federation that I've seen before include "Russia, for one" , "Group of states" , "Union of states" , "Alliance" .)