Be better than (5)
'be better than' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for surpass that I've seen before include "Exceed" , "eclipse visible" , "Outdo" , "Go one better" , "Transcend" .)
(Other definitions for trump that I've seen before include "Playing card with designated added value" , "Blast!" , "The last one to announce" , "Card from chosen suit in various card games" , "Brick" .)