Trick or gull (6)
I believe the answer is:
outwit
This clue is a double definition.
'trick' is the first definition.
(thesaurus)
'gull' is the second definition.
(I've seen this before)
'or' acts as a link.
(Other definitions for outwit that I've seen before include "Outfox" , "Be too clever for, get the better of" , "Dupe" , "Show more ingenuity than" , "Hoodwink" .)