Having neatly translated brought about the onset of death for him (7)

'the onset of death for him' is the definition.
The definition suggests a singular noun which matches the answer.

'having neatly translated brought about' is the wordplay.
'having' becomes 'd' (I am not sure about this - if you are sure you should believe this answer much more).
'translated' indicates an anagram.
'brought about' means one lot of letters goes inside another.
'neatly' with letters rearranged gives 'tynale'.
'd' inserted inside 'tynale' is 'TYNDALE'.