Senior gangster hiding newspaper (5)
I believe the answer is:
organ
'newspaper' is the definition.
(I've seen this in other clues)
'senior gangster hiding' is the wordplay.
'hiding' indicates a hidden word.
'ORGAN' can be found hidden inside 'senior gangster'.
(Other definitions for organ that I've seen before include "Brain, for example - instrument" , "Medium of information - most churches have one" , "The Times?" , "specialist magazine" , "Bodily part or large musical instrument" .)