Quiet at the back of passage (5)
I believe the answer is:
shaft
'passage' is the definition.
(I know that shaft is a type of passage)
'quiet at the back' is the wordplay.
'quiet' becomes 'sh' (both can be said to tell someone to be quiet).
'at' says to put letters next to each other.
'the back' becomes 'aft' (at the back of a ship).
'sh'+'aft'='SHAFT'
'of' is the link.
(Other definitions for shaft that I've seen before include "Arrow part" , "Long rod or column of light" , "Beam of light" , "Ray of light; treat unfairly" , "Vertical passageway, into a mine say" .)