Insinuating no rascal is telling tales (5)
I believe the answer is:
lying
'telling tales' is the definition.
(I've seen this in another clue)
'insinuating no rascal' is the wordplay.
'insinuating' becomes 'implying' (I've seen this before).
'no' suggests deleting specific letters.
'rascal' becomes 'imp' (synonyms).
'implying' with 'imp' taken out is 'LYING'.
'is' is the link.
(Other definitions for lying that I've seen before include "Prevaricating" , "Extending" , "Mendacious; recumbent" , "retailing pork pies" , "Deviating from truth" .)