Regularly inserts trap (3)
I believe the answer is:
net
'trap' is the definition.
(net is a type of trap)
'regularly inserts' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'inserts' are 'NET'.
(Other definitions for net that I've seen before include "Lattice" , "Trap; open-weave fabric" , "Trap made from mesh" , "Snare or trap" , "What separates court opponents" .)