Projecting ridge (5)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
ledge
'projecting ridge' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ledge that I've seen before include "Narrow shelf, often attached to window" , "Shelf-life projection" , "Ridge or shelf" , "found halfway up a cliff?" , "Mantelpiece" .)