Lease may be a hindrance (3)
I believe the answer is:
let
I believe this is a double definition.
'lease' is the first definition.
(I know that lease can be written as let)
'a hindrance' is the second definition.
(let can mean an obstruction)
'may be' acts as a link.
(Other definitions for let that I've seen before include "Permit; lease" , "Disappoint or fail to support - ... down" , "Allowed or rented out" , "Service that must be repeated" , "Allow; tennis fault" .)