If misquoted in a new edict, there's something lacking (7)
I believe the answer is:
deficit
'there's something lacking' is the definition.
(I've seen this before)
'if misquoted in a new edict' is the wordplay.
'misquoted' indicates an anagram (an inaccurate or mistaken spelling).
'in' indicates putting letters inside.
'a new' is an anagram indicator.
'if' is an anagram of 'fi'.
'edict' is an anagram of 'decit'.
'fi' placed within 'decit' is 'DEFICIT'.
(Other definitions for deficit that I've seen before include "Arrears" , "Show this to make a loss" , "Financial shortfall" , "Excess of liabilities over assets" , "Excess of expenditure over income" .)