Little boy taking one in with fibs (4)
I believe the answer is:
lies
'with fibs' is the definition.
'lies' can be an answer for 'fibs' (informal term for lies). I am unsure of the 'with' bit.
'little boy taking one' is the wordplay.
'little boy' becomes 'les' (short for Leslie. I am not sure about the 'little' bit.).
'taking' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'les' enclosing 'i' is 'LIES'.
'in' is the link.
Can you help me to learn more?
(Other definitions for lies that I've seen before include "pork pies" , "Fabrications" , "Terminological inexactitudes" , "Fibs" , "Untruths" .)