Rude little blighter to lie outrageously (8)
I believe the answer is:
impolite
'rude' is the definition.
(similar in meaning)
'little blighter to lie outrageously' is the wordplay.
'little blighter' becomes 'imp'.
'outrageously' indicates an anagram.
'to'+'lie'='tolie'
'tolie' anagrammed gives 'olite'.
'imp'+'olite'='IMPOLITE'
(Other definitions for impolite that I've seen before include "Bad-mannered" , "Having bad manners" , "Bad mannered" , "Ill-mannered" , "Rude, unmannerly" .)