Save edit when working, something that may de-stress one (8)
I believe the answer is:
sedative
'something that may de-stress one' is the definition.
(I know that a sedative can de-stress someone)
'save edit when working' is the wordplay.
'when working' indicates anagramming the letters (the letters must work themselves into a new order).
'save'+'edit'='saveedit'
'saveedit' is an anagram of 'SEDATIVE'.
(Other definitions for sedative that I've seen before include "having soothing effect" , "Tranquilising drug" , "Tranquilliser" , "Sleeping drug" , "Calming drug" .)