Available for renting (5)
(Another definition for tolet that I've seen is " for hire".)
'available for renting' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for to let that I've seen before include "Sign on property available to rent" , "Notice of vacancy" , "open to offers" , "Available for renting" , "Sign of the property market" .)