To break down (as solids into small pieces, powder, etc.); to be smashed to bits; destroyed.
This medicine won't break down (dissolve) because it's already expired.
That bottle was smashed to bits from a motorcycle running over it.
To break down (a solid into small pieces, powder, etc.); to destroy s.t.; to smash, crush, pound (a solid).
Who smashed a bottle on this concrete?
Crumble up (lit. break down) up that (boiled) shark meat and then cook it.