any of several small terrestrial isopods (esp. genus Oniscus) living in damp places, as under rocks
See sow bug in American Heritage Dictionary 4
noun In both senses also called slater, wood louse; also called regionally doodlebug.
Any of various small terrestrial isopod crustaceans, chiefly of the genera Oniscus and Porcellio, commonly found under logs or stones and having an oval, segmented body.