pill bug

noun

1. any of various small terrestrial isopods, especially of the genera Armadillidium and Oniscus, which can roll themselves up into a spherical shape.

pill bug

noun

1. any of various woodlice of the genera Armadillidium and Oniscus, capable of rolling up into a ball when disturbed

Word History and Origins

Origin of pill bug¹

An Americanism dating back to 1835–45