Children's story? (3)
I believe the answer is:
fib
'story?' is the definition.
(synonyms)
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 "Small lie" , "A harmless white lie" , "minor piece of fiction" , "One must be 20 [UNTRUE]" , "Petty falsehood" .)