pill bug

American  

noun

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

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pill bug British  

noun

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

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Etymology

Origin of pill bug

An Americanism dating back to 1835–45

Example Sentences

A new species of giant deep-sea isopod—a cousin to the common pill bug but more than 10 inches long—was found hiding in plain sight.

From Scientific American

I pulled the board up, releasing boll weevils, pill bugs, and a small spider from their homes.

From Literature

Instead, worms rely on a village of bacteria, molds, fungi, pill bugs and other beneficial microbes to break down the food so they can eat it with their microscopic mouths.

From Los Angeles Times

The air had a strange smell to it, too—maybe the space behind the bookcase was full of dead centipedes and millipedes and pill bugs.

From Literature

Like trilobites, three-banded armadillos, pill bugs, hedgehogs and other animals, the chiton can roll itself into a ball.

From New York Times