Get the better of, defeat (8)
I believe the answer is:
overcome
This clue is a double definition.
'get the better of' is the first definition.
(synonyms)
'defeat' is the second definition.
(I know that defeat can be written as overcome)
(Other definitions for overcome that I've seen before include "Speechless" , "Overwhelm (someone)" , "Succeed in dealing with difficulties" , "worst?" , "Emotionally affected" .)