Abnormal sort of faker (5)
I believe the answer is:
freak
'abnormal' is the definition.
(I've seen this before)
'sort of faker' is the wordplay.
'sort of' indicates anagramming the letters.
'faker' anagrammed gives 'FREAK'.
(Other definitions for freak that I've seen before include "Abnormality" , "Eccentric" , "Oddball" , "Monstrosity" , "Abnormal creature" .)