Quiet place of worship lacking energy and run down (6)
I believe the answer is:
shabby
'run down' is the definition.
(I've seen this before)
'quiet place of worship lacking energy' is the wordplay.
'quiet' becomes 'sh'.
'place of worship' becomes 'abbey' (abbey is a kind of place of worship).
'lacking' suggests deleting specific letters.
'energy' becomes 'e' (physics symbol as in E=mc2).
'abbey' with 'e' taken away is 'abby'.
'sh'+'abby'='SHABBY'
'and' is the link.
(Other definitions for shabby that I've seen before include "Worn out, dilapidated" , "Dingy; dishonourable" , "Showing signs of wear and tear" , "Faded - threadbare" , "in worn and dirty clothes" .)