EU perhaps repositioned above Britain (12)
I believe the answer is:
abbreviation
'eu perhaps' is the definition.
(EU is the abbreviation for European Union)
'repositioned above britain' is the wordplay.
'repositioned' indicates anagramming the letters.
'above'+'britain'='abovebritain'
'abovebritain' with letters rearranged gives 'ABBREVIATION'.
(Other definitions for abbreviation that I've seen before include "RAF, for example" , "Shortened form of a word or phrase" , "Shortening - above Britain (anag)" , "EU, for example" , "Device linking 1d, 7, 15 and 19" .)