Low toll for berth (7)
I believe the answer is:
mooring
'berth' is the definition.
('mooring' can be a synonym of 'berth')
'low toll' is the wordplay.
'low' becomes 'moo' ('moo' can be a synonym of 'low').
'toll' becomes 'ring' (I've seen this before).
'moo'+'ring'='MOORING'
'for' acts as a link.
(Other definitions for mooring that I've seen before include "where boat is secured" , "stopping" , "Ship's berth" , "Tying up (a boat)" , "Place to keep a boat" .)