Left at church, on the door (5)
I believe the answer is:
latch
'door' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'left at church on' is the wordplay.
'left' becomes 'l' (common abbreviation).
'church' becomes 'ch' (common abbreviation).
'on' means one lot of letters go next to another.
'l'+'at'+'ch'='LATCH'
'the' acts as a link.
Can you help me to learn more?
(Other definitions for latch that I've seen before include "retainer" , "Door securer" , "Door catch" , "Device for opening door" , "Gate fastening" .)