Definition of "bristletail"

Any of various small, active six-legged arthropods that have two or three bristles at the ends of their abdomens and that do not have wings. These were formerly classified together in the insect subclass Apterygota or the order Thysanura but are no longer considered closely related:

1. jumping bristletails in the insect order Archaeognatha  examples

2. insects in the order Zygentoma such as silverfish and firebrats  examples

3. two-pronged bristletails in the hexapod order Diplura  examples