Disperse liquid in small dish (8)
I believe the answer is:
'disperse liquid' is the definition.
'in small dish' is the wordplay.
'in small' becomes 's' (abbreviation - e.g. clothes size. I am not sure about the 'in' bit.).
'dish' becomes 'platter' (platter is a kind of dish).
(Other definitions for splatter that I've seen before include "Of a cloud in space" , "Prattles (anag)" , "Splash noisily, about" , "Splash (across)" , "Splash with sticky liquid" .)