Slosh (5)
I believe the answer is:
spill
'slosh' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for spill that I've seen before include "Thin piece of wood or rolled paper to light a fire" , "Accidentally cause to overflow" , "Waste from container" , "Upset - lighter" , "Cause to fall from horse" .)