Loch with a legend (4)
I believe the answer is:
ness
'loch with a legend' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ness that I've seen before include "Scottish lake with traditional monster" , "Where you're reputed to see monster" , "Scottish Loch famed for monster" , "Headland, promontory" , "head" .)