Terrestrial isopod having an oval segmented body (a shape like a sow) WordNet 3.0 & Open English WordNet

A terrestrial crustacean that is a member of the suborder Oniscidea. It has a rigid, segmented, calcareous exoskeleton and fourteen jointed limbs. It is usually found in damp, dark places, such as under rocks and logs. OmegaWiki

Any of the terrestrial isopod crustaceans of suborder Oniscidea, which have a rigid, segmented exoskeleton, often being capable of rolling into a ball, and feed only on dead plant matter, usually living in damp, dark places, such as under stones or bark. Wiktionary

Any species of suborder Oniscidea. Wiktionary (translation)