German fellow shows bum after stripping (4)
I believe the answer is:
otto
'german fellow' is the definition.
(common German name)
'bum after stripping' is the wordplay.
'bum' becomes 'bottom' (synonyms).
'after stripping' indicates the central letters (the word is stripped of its external letters).
The centre of 'bottom' is 'OTTO'.
'shows' is the link.
(Other definitions for otto that I've seen before include "Something essential" , "Rose produces this" , "Rose petal oil; Bismarck's name" , "Palindromic German boy's name" , "Rose oil - Holy Roman Emperor" .)