Idleness indeed (8)
I believe the answer is:
inaction
'idleness' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for inaction that I've seen before include "Inertia" , "Sluggishness" , "Stasis" , "lack of engagement" , "Sloth" .)