Clear trap (3)
I believe the answer is:
net
I believe this clue is a double definition.
'clear' is the first definition.
(as in net profit)
'trap' is the second definition.
(net is a type of trap)
(Other definitions for net that I've seen before include "Tennis equipment" , "It's see-through" , "Butterfly trap" , "Mesh; profit" , "Fish-catcher" .)