Lose money on Scottish island (6)
I believe the answer is:
mislay
'lose' is the definition.
('mislay' can be a synonym of 'lose')
'money on scottish island' is the wordplay.
'money' becomes 'm' (abbreviation in economics).
'on' means one lot of letters go next to another.
'scottish island' becomes 'islay' (I've seen this before).
'm'+'islay'='MISLAY'
(Other definitions for mislay that I've seen before include "Put something aside and forget where" , "Lose (something)" , "Temporarily not find" , "Put in wrong place, lose temporarily" , "Put (something) where it can't be found" .)