Spot, splash (7)
I believe the answer is:
splodge
This clue is a double definition.
'spot' is the first definition.
(I know that splodge is a type of spot)
'splash' is the second definition.
(I have seen 'big splash' mean 'splodge' so perhaps 'splash' could also mean 'splodge')
(Other definitions for splodge that I've seen before include "Dirty mark" , "big splash" , "Spot, splash, smear" , "Messy spot" , "Irregular blot" .)