Spiritlessness (6)
I believe the answer is:
apathy
'spiritlessness' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for apathy that I've seen before include "Lack of excitement" , "Lack of interest in things in general" , "Lack of emotion and interest" , "Indifference, emotionlessness" , "Complete lack of interest, indifference" .)