In a mine, the hush at the rear (5)
I believe the answer is:
shaft
'in a mine' is the definition.
I can't tell whether this definition defines the answer.
'hush at the rear' is the wordplay.
'hush' becomes 'sh' (both are used to tell someone to be quiet).
'at' is a charade indicator (letters next to each other).
'the rear' becomes 'aft' (I've seen this before).
'sh'+'aft'='SHAFT'
'the' is the link.
Can you help me to learn more?
(Other definitions for shaft that I've seen before include "Ray (of light), access to mine" , "Body of an arrow" , "fleece" , "Beam of light" , "Vertical excavation" .)