Settled muddle over sled (8)
I believe the answer is:
resolved
'settled' is the definition.
('resolve' can be a synonym of 'settle')
'muddle over sled' is the wordplay.
'muddle' indicates anagramming the letters.
'over'+'sled'='oversled'
'oversled' anagrammed gives 'RESOLVED'.
(Other definitions for resolved that I've seen before include "Settled, decided" , "tackled crossword again?" , "Decided, determined" , "Not put off" , "Decided firmly on a course of action" .)