Ruling is in code ridiculously (8)
I believe the answer is:
decision
'ruling' is the definition.
(I've seen this in another clue)
'is in code ridiculously' is the wordplay.
'ridiculously' indicates anagramming the letters.
'is'+'in'+'code'='isincode'
'isincode' anagrammed gives 'DECISION'.
(Other definitions for decision that I've seen before include "Outcome of discussion" , "A judgment or choice" , "Verdict, outcome" , "A reasoned judgement about something, no dithering" , "Result!" .)