Charge the boy nothing to go in (4)
I believe the answer is:
load
'charge' is the definition.
('load' can be a synonym of 'charge')
'the boy nothing to go in' is the wordplay.
'the boy' becomes 'lad' (lad is a kind of boy**).
'nothing' becomes 'o' (looks like zero - 0).
'to go in' is an insertion indicator.
'lad' placed around 'o' is 'LOAD'.
(Other definitions for load that I've seen before include "that's put on commercial vehicle" , "pack" , "Charge a gun" , "Amount" , "Goods carried by a large vehicle" .)