Exploit source of inspiration when lives lost (6)
I believe the answer is:
misuse
'exploit' is the definition.
(thesaurus)
'source of inspiration when lives lost' is the wordplay.
I cannot quite understand how this works, but
'when' could be 'e' (I've seen this in other clues) and 'e' is present in the answer.
'lives' could be 'is' ('be' can be a synonym of 'live') and 'is' is present in the answer.
The remaining letters 'mus' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for misuse that I've seen before include "Improper application" , "Ill-treatment" , "bad practice" , "Employ or apply wrongly" , "Put to the wrong purpose" .)