Flowing grease settles (6)
I believe the answer is:
agrees
'settles' is the definition.
(settle can mean to agree or resolve)
'flowing grease' is the wordplay.
'flowing' indicates anagramming the letters.
'grease' with letters rearranged gives 'AGREES'.
(Other definitions for agrees that I've seen before include "Holds the same opinion" , "Assents, concurs" , "Accedes or concurs" , "is in accord" , "Shakes hands" .)