Changelessness (6)
I believe the answer is:
stasis
'changelessness' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for stasis that I've seen before include "No progressive state" , "lack of progress" , "Inactivity or stoppage of circulation" , "Secret police force's" , "Abnormal state in which the flow of blood is stopped" .)