Left unfinished, religious image in place of pillars (7)
I believe the answer is:
portico
'place of pillars' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'left unfinished religious image' is the wordplay.
'left' becomes 'port' (left side of a ship - opposite of starboard).
'unfinished' means to remove the last letter.
'religious image' becomes 'icon' (I've seen this before).
'icon' with its last letter taken away is 'ico'.
'port'+'ico'='PORTICO'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for portico that I've seen before include "Covered porch with supporting columns" , "Posh covered entrance to building" , "A number of columns" , "series of columns" , "building construction" .)
