Endopterygota

Etymology
From +  +, reflecting the fact that the nymphs (larvae) of winged species bear their wing rudiments internally; compare.

Usage notes
Endopterygota typically undergo a "complete" metamorphosis, during which their wings develop internally during the pupal phase and appear in the emerging adult. The grouping is thus also called. Contrast this with the (in which the wings develop externally and the pupal stage is omitted) and  (which are primitively wingless). Note that fleas, for example, are not primitively wingless, but are descended from winged insects.

The complete metamorphosic life cycle is: egg → larva → pupa → adult or imago.