Lose a thousand on a Scottish isle (6)
I believe the answer is:
mislay
'lose' is the definition.
(I know that mislay is a kind of lose)
'a thousand on a scottish isle' is the wordplay.
'a thousand on a scottish' becomes 'm' (I can't explain this - if you can you should believe this answer much more).
'isle' becomes 'islay' (Scottish island).
'm'+'islay'='MISLAY'
Can you help me to learn more?
(Other definitions for mislay that I've seen before include "Put something aside and forget where" , "Set in wrong location" , "Lose (something)" , "Put (something) where it can't be found" , "Lose (an item)" .)