Absence of stress regarding nastiness (7)
I believe the answer is:
respite
'absence of stress' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'regarding nastiness' is the wordplay.
'regarding' becomes 're' (re can mean regarding, concerning).
'nastiness' becomes 'spite' (synonyms).
're'+'spite'='RESPITE'
Can you help me to learn more?
(Other definitions for respite that I've seen before include "interruption" , "Brief period of rest" , "Period of relief (from unpleasant thing)" , "Pause from exertion, etc" , "Pause; reprieve" .)