Insect with a thousand enemies (6)
I believe the answer is:
mantis
'insect' is the definition.
(mantis is a kind of insect)
'with a thousand enemies' is the wordplay.
'with' indicates putting letters inside.
'a' becomes 'an'.
'thousand' becomes 'm' (Roman numeral for a thousand).
'enemies' becomes 'tis' (I can't justify this - if you can you should give a lot more credence to this answer).
'm'+'tis'='mtis'
'an' put inside 'mtis' is 'MANTIS'.
Can you help me to learn more?
(Other definitions for mantis that I've seen before include "Actually it preys rather than prays" , "Carnivorous insect, which rests as if in prayer" , "Insect in attitude of prayer" , "It appears to be praying but is more likely preying" , "Praying ..., long-bodied, large-eyed insect" .)