You could call it a pork pie (3)
I believe the answer is:
fib
'you' is the definition.
Both the definition and answer are singular nouns.
Maybe they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for fib that I've seen before include "Story" , "One must be 20 [UNTRUE]" , "Trivial lie" , "A harmless white lie" , "Little white lie" .)