Bum snare catching bottom in the end (5)
I believe the answer is:
tramp
'bum' is the definition.
('tramp' can be a synonym of 'bum')
'snare catching bottom in the end' is the wordplay.
'snare' becomes 'trap' ('trap' can be a synonym of 'snare').
'catching' is an insertion indicator.
'in the end' suggests the final letters.
The final letter of 'bottom' is 'm'.
'trap' placed around 'm' is 'TRAMP'.
(Other definitions for tramp that I've seen before include "Footslog" , "Walk heavily like hobo" , "Itinerant" , "woman who's promiscuous?" , "Vagrant, drifter" .)