Evacuation chairs sat abandoned (9)
I believe the answer is:
catharsis
'evacuation' is the definition.
(thesaurus)
'chairs sat abandoned' is the wordplay.
'abandoned' is an anagram indicator (the original order is abandoned).
'chairs'+'sat'='chairssat'
'chairssat' with letters rearranged gives 'CATHARSIS'.
(Other definitions for catharsis that I've seen before include "emotional relief" , "Emotional purge" , "Emotional release" , "relief of tensions" , "Release of feelings" .)