Charge for ring (4)
I believe this is a double definition.
'charge' is the first definition.
(toll is a kind of charge)
'ring' is the second definition.
(tolling is a kind of ringing)
'for' is the link.
(Other definitions for toll that I've seen before include "Charge (to use road)", "Fee for road/bridge", "Crossing fee", "repeated ringing", "Form of road tax".)