Reg and Ian possibly recover (6)
I believe the answer is:
regain
'recover' is the definition.
(I know that recover can be written as regain)
'reg and ian possibly' is the wordplay.
'and' means one lot of letters go next to another.
'possibly' indicates anagramming the letters.
'ian' with letters rearranged gives 'ain'.
'reg'+'ain'='REGAIN'
(Other definitions for regain that I've seen before include "Possess once more for regina" , "Recover, retrieve" , "Get back (previously owned object)" , "Get back, recover the use of" , "Take back (the Ashes, for example)" .)