Vegetation right outside church (6)
I believe the answer is:
lichen
'vegetation' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'right outside church' is the wordplay.
'right' becomes 'lien' (I've seen this before).
'outside' means one lot of letters goes inside another.
'church' becomes 'ch' (common abbreviation).
'lien' going around 'ch' is 'LICHEN'.
Can you help me to learn more?
(Other definitions for lichen that I've seen before include "Plants found on tree trunks etc" , "Tiny plants found on rocks, tree-trunks etc" , "Plant growing on stone" , "Compound plant not unlike to moss in appearance" , "Crusty, tufty growth on trees and stones" .)