Take the rest as pure fiction (3)
I believe the answer is:
lie
'fiction' is the definition.
(I've seen this in another clue)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lie that I've seen before include "buried" , "Porky" , "Falsity" , "Piece of fiction" , "Disinformation" .)