Get the better of (6)
'get the better of' is the definition.
(both can mean to outsmart)
This is all the clue.
(Other definitions for outwit that I've seen before include "Intellectually get the better of" , "Outsmart" , "To appear smarter" , "Get the better of by being smarter" , "Outfox" .)
'get the better of' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for outsmart that I've seen before include "Defeat by more skilful manoeuvring" , "Fox; deceive" , "Defeat by skillful maneuvering" , "Fool" , "Excel in cleverness" .)