Stage between larva and imago
I believe the answer is:
pupa
'stage between larva and imago' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pupa that I've seen before include "appearance of immaturity" , "One is growing" , "developing creature" , "So peacock may have appeared" , "Stage of an insect's development" .)