Leaving out nothing to do with life's work perhaps (8)
I believe the answer is:
omission
'leaving out' is the definition.
(thesaurus)
'nothing to do with life's work perhaps' is the wordplay.
I cannot really see how this works, but
'nothing' could be 'o' (looks like zero - 0) and 'o' is found within the answer.
'work' could be 'mission' (mission is a kind of work) and 'mission' is found within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for omission that I've seen before include "Deficiency" , "Lack" , "type of sin" , "Failure to include" , "Act of leaving out" .)