How to fool a child? (3)
I believe the answer is:
kid
This clue is a double definition.
'how to fool' is the first definition.
(I know that kid is a kind of befool)
'a child?' is the second definition.
(I know that child can be written as kid)
(Other definitions for kid that I've seen before include "Joke" , "Deceive - child" , "Josh" , "To fool; young animal" , "In slang, young child or goat" .)