Predatory insect (6)
I believe the answer is:
mantis
'predatory insect' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mantis that I've seen before include "Predatory insect" , "Actually it preys rather than prays" , "Insect often seen in praying posture" , "It appears to be praying but is more likely preying" , "Large insect (sometimes praying?)" .)