Many an ant is apparently devout! (6)
I believe the answer is:
mantis
'apparently devout' is the definition.
I can't judge whether this definition defines the answer.
'many an ant is' is the wordplay.
'many' becomes 'M' (Roman numeral for a thousand).
'm'+'ant'+'is'='MANTIS'
Can you help me to learn more?
(Other definitions for mantis that I've seen before include "Insect often seen in praying posture" , "may be praying" , "Large-eyed insect, looks as if it's praying" , "Large insect (sometimes praying?)" , "Preying animal, the female of which is deadlier than the male!" .)