Spot old European currency (4)
I believe the answer is:
mark
This clue is a double definition.
'spot' is the first definition.
(I know that spot is a more specific form of the action mark)
'old european currency' is the second definition.
(former German currency)
(Other definitions for mark that I've seen before include "Spot - sign - currency" , "Former German monetary unit" , "Take note of" , "Indicate" , "Former German currency" .)