Councillor essentially avoids anxiety in retirement (8)
I believe the answer is:
solitude
'retirement' 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 solitude that I've seen before include "Privacy" , "Absence of company" , "Isolation, loneliness" , "Seclusion" , "Isolated state - slide out (anag)" .)