Vagrant male in role reversal (5)
I believe the answer is:
tramp
'vagrant' is the definition.
(thesaurus)
'male in role reversal' is the wordplay.
'male' becomes 'm' (common abbreviation).
'in' indicates putting letters inside.
'role' becomes 'part' ('part' can be a synonym of 'role').
'reversal' shows that the letters should be reversed in order.
'm' inserted into 'part' is 'pmart'.
'pmart' in reverse letter order is 'TRAMP'.
(Other definitions for tramp that I've seen before include "Hike" , "Disreputable wanderer" , "Ship, possibly" , "Walk with heavy steps like hobo" , "Derelict - ship" .)