Catch in one trap (3)
I believe the answer is:
'catch' is the definition.
(net can mean to catch)
'in one trap' is the wordplay.
'in' says the answer is hidden in the clue.
'NET' is hidden in the letters of 'one trap'.
(Other definitions for net that I've seen before include "device to divide the court" , "Lattice" , "Fish-catching mesh" , "Overall; mesh" , "Clear profit or gain" .)