Not commonly used.
The Exopterygota differ from the Endopterygota in that they generally undergo an "incomplete" metamorphosis. Their life cycle typically lacks a clearly defined pupal phase. In winged species the nymphs (larvae) generally bear external wing rudiments, which immature members of the Endopterygota do not.
The Exopterygota life cycle is: egg → larva or nymph → adult or imago. The transformation from larva to adult is gradual and proceeds by moulting.
For comparison, the complete metamorphosic life cycle is: egg → larva → pupa → adult or imago.
From Ancient Greek ἔξω (exo, “outside”) + πτερόν (pteron, “wing”) + New Latin -ota (“having”), reflecting the fact that the nymphs (larvae) of winged species bear their wing rudiments externally; compare Endopterygota.