Courageous? Not very - It's a Scottish bank! (4)
I believe the answer is:
brae
'a scottish bank' is the definition.
(I've seen this before)
'courageous? not very' is the wordplay.
'courageous?' becomes 'brave' ('brave' can be a synonym of 'courageous').
'not' is a deletion indicator.
'very' becomes 'v' (abbreviation).
'brave' with 'v' taken out is 'BRAE'.
'it's' acts as a link.
(Other definitions for brae that I've seen before include "Steep bank or hillside" , "Steep bank (Scots)" , "Upland area in Scotland" , "Scottish hill slope" , "Bear up on Scottish hillside" .)