British imperialism absorbs the fellow (3)
I believe the answer is:
him
'the fellow' is the definition.
'british imperialism absorbs' is the wordplay.
'absorbs' indicates the answer is hidden within the clue.
'HIM' is hidden in the letters of 'british imperialism'.
(Other definitions for him that I've seen before include "Proper character" , "That man" , "Objective male pronoun" .)