Spirit of a group (5)
I believe the answer is:
ethos
'spirit of a group' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ethos that I've seen before include "Distinctive group attitudes" , "Group's distinctive character" , "Characteristic spirit of a community - for those" , "Those (anag.)" , "Characteristic attitudes" .)