One charged over breaking in (3)
I believe the answer is:
ion
'one charged' is the definition.
(type of charged particle)
'over breaking in' is the wordplay.
'over' becomes 'o' (cricket abbreviation).
'breaking' means one lot of letters goes inside another.
'o' placed within 'in' is 'ION'.
(Other definitions for ion that I've seen before include "Charged atom/molecule" , "Particle (phys.)" , "Subatomic particle" , "Electrically-charged particle" , "Eletrically charged particle" .)