Religion accordingly includes suggestion (6)
I believe the answer is:
shinto
'religion' is the definition.
(I know that Shinto is a type of religion)
'accordingly includes suggestion' is the wordplay.
'accordingly' becomes 'so' (synonyms).
'includes' is an insertion indicator.
'suggestion' becomes 'hint' (hint is a kind of suggestion).
'so' enclosing 'hint' is 'SHINTO'.
(Other definitions for shinto that I've seen before include "Japanese cult" , "State religion of Japan until 1945" , "Japanese religion revering ancestors" , "Japenese religion revering ancestors" , "Japanese worship" .)