Tally of money ending in many killings? (8)
I believe the answer is:
coincide
'tally' is the definition.
(I know that coincide is a more specific form of the action tally)
'money ending in many killings?' is the wordplay.
'money' becomes 'coin' (coin is a type of money).
'ending in many killings?' becomes 'cide' (suffix in homicide, suicide etc).
'coin'+'cide'='COINCIDE'
'of' is the link.
(Other definitions for coincide that I've seen before include "Happen together" , "Show correspondence" , "Happen simultaneously" , "Occur simultaneously" , "Correspond" .)