Decree found in Japanese dictionary (5)
I believe the answer is:
edict
'decree' is the definition.
(I know that decree can be written as edict)
'in japanese dictionary' is the wordplay.
'in' indicates the answer is hidden within the clue.
'EDICT' is hidden within 'japanese dictionary'.
'found' is the link.
(Other definitions for edict that I've seen before include "Canon" , "An official command" , "Legally-binding order" , "Proclamation, law" , "Cited (anag) - proclamation" .)