Kills the people accepting a credit (9)
I believe the answer is:
massacres
'kills' is the definition.
(massacre is a kind of kill)
'the people accepting a credit' is the wordplay.
'the people' becomes 'masses' ('masses' can be a synonym of 'people'**).
'accepting' means one lot of letters goes inside another.
'credit' becomes 'cr'.
'a'+'cr'='acr'
'masses' going around 'acr' is 'MASSACRES'.
(Other definitions for massacres that I've seen before include "Acts of slaughter" , "kills a lot" , "Indiscriminate slaughters" , "Large-scale killings" , "Atrocities" .)