Charge the boy in possession of the ring (4)
I believe the answer is:
load
'charge' is the definition.
('load' can be a synonym of 'charge')
'the boy in possession of the ring' is the wordplay.
'the boy' becomes 'lad' (lad is a kind of boy**).
'in possession of' indicates putting letters inside (has inside).
'the ring' becomes 'o'.
'lad' placed around 'o' is 'LOAD'.
(Other definitions for load that I've seen before include "Goods carried by a large vehicle" , "Weight, source of pressure" , "Cargo - burden" , "that's put on commercial vehicle" , "Charge a gun" .)