So the reformed show spirit (5)
I believe the answer is:
ethos
'spirit' is the definition.
(I've seen this before)
'so the reformed' is the wordplay.
'reformed' indicates anagramming the letters.
'so'+'the'='sothe'
'sothe' anagrammed gives 'ETHOS'.
'show' is the link.
(Other definitions for ethos that I've seen before include "Characteristic attitudes" , "Distinctive traits of a culture, time etc" , "Characteristic spirit, of a culture say" , "Characteristic culture of a culture or time" , "Spirit of a culture/age" .)