Mercenary displaying hot anger departs (5)
I believe the answer is:
hired
'mercenary' is the definition.
(thesaurus)
'hot anger departs' is the wordplay.
'hot' becomes 'h'.
'anger' becomes 'ire' ('ire' can be a synonym of 'anger').
'departs' becomes 'd' (common abbreviation e.g. train timetables).
'h'+'ire'+'d'='HIRED'
'displaying' acts as a link.
(Other definitions for hired that I've seen before include "Employed for wages" , "Rented out" , "Taken into service" , "Paid to work" , "Engaged for wages" .)