A light on the hill by the church (5)
I believe the answer is:
torch
'a light' is the definition.
(torch is a kind of light)
'the hill by the church' is the wordplay.
'the hill' becomes 'tor' (tor is a kind of hill).
'by' means one lot of letters go next to another.
'the church' becomes 'ch' (common abbreviation).
'tor'+'ch'='TORCH'
'on' is the link.
(Other definitions for torch that I've seen before include "Link" , "Flashlight" , "Set alight deliberately" , "Burn maliciously" , "Small portable battery-powered electric lamp" .)