Shelflike projection (5)
I believe the answer is:
ledge
'shelflike projection' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ledge that I've seen before include "Narrow projecting shelf as from window" , "Projecting ridge on a mountain" , "Mantelpiece" , "Ridge or shelf" , "Sill" .)